- Email: [email protected]
Morphology of diamond single crystals grown in the Fe-Co-Mg-C system
Journal of Crystal Growth 507 (2019) 327–331
Contents lists available at ScienceDirect
Journal of Crystal Growth journal homepage: www.elsevier.com/locate/jcrysgro
Morphology of diamond single crystals grown in the Fe-Co-Mg-C system a,⁎
a
b
a
T
a
T.V. Kovalenko , V.V. Lysakovskyi , V.M. Kvasnytsya , S.O. Ivakhnenko , O.M. Suprun , A.V. Burcheniaa a b
V. Bakul Institute for Superhard Materials, National Academy of Sciences of Ukraine, str. Avtozavods’ka 2, Kyiv 04074, Ukraine M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences of Ukraine, pr. Palladina 34, Kyiv 03142, Ukraine
A R T I C LE I N FO
A B S T R A C T
Communicated by P. Rudolph
Diamond single crystals in a Fe-Co alloy with addition of 5 and 10 wt.% Mg by temperature gradient method were grown and their morphology was studied. For crystals obtained in the Fe-Co alloy with 5 wt.% Mg, the faces of octahedron, cube, rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} were observed. When the magnesium content in the solvent-alloy increase up to 10 wt.% under the same growth conditions the tetragontrioctahedron {3 1 1} faces on diamond crystals were absent. The topography of diamond crystals faces grown in different systems indicates that octahedron and cube are active growth forms with their growth pyramids, and rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} are forms of passive growth.
Keywords: A1.Crystal morphology A2. Single crystal growth A2. Growth from high temperature solutions B1. Diamond
1. Introduction The study of diamond crystallization in various systems at high pressures and high temperatures is of great interest in connection with the study of mechanisms of nucleation and crystal growth and the possibility of obtaining diamond single crystals with different properties. Most of the researches were carried out in growth systems using solvents based on transition metals (Fe, Co, Ni) [1–8]. Recently considerable attention has been paid to the search for new solvents containing magnesium [9–13]; as it was established earlier in Mg-based systems, it is possible to grow type IIb diamond single crystals, which possess semiconductor properties with growth rates exceeding the growth rates of diamonds in systems based on transition metals in 8–10 times [10]. The first works on the crystallization of diamonds in growth systems with magnesium were carried out in the 1990s [9]. However, the limited possibilities for creating the necessary high pressure and temperature (up to 8.5 GPa and 2200 °C, respectively) did not allow to study of the regularities of boron incorporation into the diamond crystal lattice and the production of semiconductors. In latest years, developed methodological approaches of diamond single crystals growth at extreme pressures and temperatures have allowed studying of regularities of diamond crystallization in magnesium-based systems. Resent studies have shown considerable prospects of these systems in terms of controlled doping of diamond with boron and nitrogen in the growth process. Diamond crystals grown in magnesium-based systems, in addition to semiconductor properties and extremely high growth
⁎
rates, have a number of unique features such as extraordinary microand macro-morphology, internal structure [14]. The morphology of diamond single crystals grown in Mg-based systems is different and depends significantly on the composition of the growth system [14–16]. There are two main habit types – cubic and cube-octahedron. The faces of the {1 1 1} and {1 0 0} are the main faces for crystals grown in Mg-Cu-C, Mg-Ni-C, Mg-Cu-Ni-C, Mg-Ag-Ni-C systems at a pressure of 6.3 GPa and a temperature of 1550–1650 °C [16]; at a magnesium content of 40–45 at.% crystal growth occurs under conditions of suppression of the {1 0 0} faces and the formation of antiscale crystal. The faces of the tetragon-trioctahedron {3 1 1} are formed when the faces {1 1 1} and {1 0 0} are completely wedged out; a decreasing of magnesium content in such systems and an increasing of growing temperature lead to reduce facial suppression. In the Mg-Si-C system [17] with silicon content of 1 wt.%, approximately the same development of the {1 0 0} and {1 1 1} faces and the growth of the cube-octahedral crystals are observed. When ≥2 wt.% Si is added to the growth system morphology of crystals is determined by the dominant {1 1 1} faces. In order to obtain information on the diamond crystallization in magnesium-based systems, Fe-Co-Mg-C system with different magnesium content was investigated. Experiments were carried out using alloys-solvents based on Fe-Co with 5 wt.% Mg and 10 wt.% Mg at a pressure of 6.0–6.5 GPa and a temperature of 1420–1500 °C.
Corresponding author. E-mail address: [email protected] (T.V. Kovalenko).
https://doi.org/10.1016/j.jcrysgro.2018.11.040 Received 18 October 2018; Received in revised form 29 November 2018; Accepted 30 November 2018 Available online 01 December 2018 0022-0248/ © 2018 Elsevier B.V. All rights reserved.
Journal of Crystal Growth 507 (2019) 327–331
T.V. Kovalenko et al.
Fig. 1. X-ray picture of diamond single crystal grown in Fe-Co allow with 10 wt. % Mg.
Fig. 2. Raman spectra of diamond single crystals grown in Fe-Co alloy with 5 wt.% Mg (1) and 10 wt.% Mg (2).
Fig. 3. SEM images of diamond single crystals (o-octahedron, c-cube, t-tetragon-trioctahedron {3 1 1}, r-rhomb-dodecahedron) obtained in the Fe-Co-MgC system. (a) Fe-Co alloy with 10 wt.% Mg (mass 0.12 ct); (b, c) – Fe-Co alloy with 5 wt.% Mg (0.17 and 0.13 ct).
2. Experiment The experiments were carried out at high pressure and high temperature in large volume cubic high pressure apparatus 6 × 2.8·104 MN. A cubic container with dimensions of 58 × 58 × 58 mm was used. Fe-Co alloy, graphite GSM1 and Mg purity 99.99 with a fraction of 30–40 μm were used in the experiments. Graphite and Mg were mixed thoroughly for 2 h. Then the mixed powder was pre-pressed into a disk at a pressure 0.15 GPa. The Mg additives used in the experiments were 5 wt.% and 10 wt.%. The growing process was carried out by the temperature gradient method [18,19], at a pressure in the range of 6.0–6.5 GPa and a temperature of 1420–1500 °C. The pressure was calibrated by the pressure induced phase transitions of bismuth and thallium [20]. The temperature was measured by the PtRh30/PtRh6 thermocouple. The accuracy values of the pressure and temperature measurement was ± (0.2 ÷ 0.4) GPa and ± (40 ÷ 60) °C, respectively. After the HPHT experiments metal solvent and graphite were removed by boiling the sample in acid. The X-ray diffraction (XRD) was performed using DRON x-ray diffractometer with CuKα x-ray source. Raman spectra were obtained with using a triple Raman spectrometer T-64000 Horiba Jobin-Yvon, equipped with electrically cooled CCD detector. The excitation of the
Fig. 4. An idealized image of a diamond single crystal obtained in a Fe-Co alloy with 5 wt.% Mg.
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Fig. 5. An idealized image of a diamond single crystal obtained in a Fe-Co alloy with 10 wt.% Mg. Fig. 6. Topography of diamond single crystals faces grown in the Fe-Co alloy with 5 wt.% Mg. (a and b) – the faces of the {1 1 1} and {1 0 0} forms have clear elongated lamellar formations with a transition to parallel strokes, (c and d) the faces of the {1 1 0} and {3 1 1} forms ornamented with parallel strokes along the octahedron plane.
Fig. 3 shows diamond crystals obtained in the Fe-Co-Mg-C system with different magnesium content grown by temperature gradient method with growth rates ∼4–5 mg/h. Crystals grown in the Fe-Co alloy with 5 wt.% Mg have the following set of simple forms {1 1 1}–{1 0 0}–{1 1 0}–{3 1 1} (Figs. 3 and 4); the cube and octahedron faces are developed on all crystals. The rhomb-dodecahedron often has an incomplete development, whereas the tetragon-trioctahedron {3 1 1} is almost always full. Usually the octahedron faces dominate on crystals: the ratio of the areas of the octahedron and cube faces is approximately 3: 1 (∼65 ÷ 85% and ∼15 ÷ 35%, respectively). The boundaries of the rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} are present in the form of blunt ribs between the edges of the octahedron and the cube. A set of simple crystal forms and their development in single crystals obtained in the Fe-Co alloy with 10 wt.% Mg (Figs. 3 and 5) vary depending on the growing conditions. A cube-octahedral crystal was grown at the maximum temperature (Fig. 5a); in other cases, at a lower temperature, cubo-octahedral faces with poorly developed rhomb-dodecahedron facets were observed, and the rhomb-dodecahedron is usually incomplete. Unlike the idealized images of diamond crystals (Figs. 4 and 5), the faces of different shapes of their real crystals have different development (Fig. 3). The faces of the octahedron are dominated, further,
Raman scattering was performed by a 532 nm diode-pumped solid-state laser. The surface morphologies were examined with an optical microscope (OM), a goniometer GD-1, and a scanning electron microscope (SEM). 3. Results and discussion XRD and Raman spectroscopy are very effective technique to characterize diamond crystals [21]. Fig. 1 represents a typical X-ray diffraction pattern obtained from diamond single crystal grown in the Fe-Co alloy with 10 wt.% Mg. All crystals grown in Fe-Co-Mg-C system with different magnesium content have similar XRD picture. XRD spectrum shows characteristic diamond peaks at (2θ) 43.93° and 75.37 corresponding to diamond {1 1 1} and {2 2 0} reflections, respectively [22]. Raman spectroscopy was used to characterize the diamond crystal grown in Fe-Co-Mg-C system (Fig. 2). The Raman peaks values and FWHM (full width at half maximum) indicate the relative quality of obtained crystals [23]. All diamonds grown in Fe-Co-Mg-C system with different magnesium content display a sharp band at 1332.5 cm−1. FWHM is observed to be very low (3.2 cm−1), that indicate the good crystalline quality of crystals. 329
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with 10 wt.% Mg (Fig. 7). On the octahedron faces, sets of plates at an angle of 60° relative to one another are observed. The boundaries of the rhomb-dodecahedron and some faces of the tetragon-trioctahedron {3 1 1} are ornamented by parallel strokes along the (1 1 1) plane, which indicates their passive growth. The results of topographic researches indicate that the crystals in both systems grew layer by layer (1 1 1) and (1 0 0), with the predominant development of the (1 1 1) planes. This is because the octahedron and the cube have different own growth pyramids. The faces of the rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} apparently do not have their own growth pyramids and are formed by the degeneration of the faces of the octahedron and the cube. There are no signs of spiral growth of the octahedron and cube faces. Draws attention to the fact that the reliefs of the octahedron and the cube faces for crystals obtained in solvents with different Mg content (5 and 10 wt.%, Figs. 4 and 5, respectively) significantly differ from each other. The faces of the octahedron and the cube (Fig. 7) are covered by differently sized and shaped subparallel-oriented lamellar figures, while the faces of the rhomb-dodecahedron are ornamented by parallel strokes along the (1 1 1) plane. At high magnifications, both growth and dissolution sculptures are fixed. On the octahedron faces, patterns of triangular and hexagonal cavities typical for diamond crystals are observed; sculptures of polycentric and dendritic growth are also present; on the cube faces patterns of quadrangular cavities and sculptures of dendritic growth are observed. Cavities on the faces of the octahedron reveal a very thin layering along (1 1 1). 4. Conclusions 1. Increasing of magnesium content in the growth system based on FeCo from 5 to 10 wt.% leads to a change in the degree of diamond single crystals faces development; for crystals obtained with a large magnesium content, the tetragon-trioctahedron faces {3 1 1} are wedged out. 2. Apparently, increasing of magnesium content in the growth system stabilizes the growth of the octahedron and the cube faces, slowing their growth and contributing to their area development. 3. Microrelief of diamond single crystals faces grown in the Fe-CoMg–C system indicate layerwise growth mechanism with generation of faces at both edges and vertices, and polycentrically. Appendix A. Supplementary material Supplementary data to this article can be found online at https:// doi.org/10.1016/j.jcrysgro.2018.11.040.
Fig. 7. Topography of the faces of various forms of diamond single crystals grown in the Fe-Co alloy with 10 wt.% Mg, on which {3 1 1} faces are absent.
References according to the degree of development, a cube, tetragon-trioctahedron {3 1 1} are presented, faces of the rhomb-dodecahedron are less developed. It should be noted that the increasing of magnesium content in the growth system based on Fe-Co from 5 to 10 wt.% leads to a change in the degree of diamond single crystals faces development; for crystals obtained with a large magnesium content, the tetragon-trioctahedron faces {3 1 1} are wedged out. Increasing of magnesium content in the growth system leads to a change in the surface energy of the crystal and, accordingly, to the formation of the equilibrium form of the crystal formed by planar faces [24,25]. The topography of the faces of crystals grown in the Fe-Co-Mg–C system was studied. For crystals grown in Fe-Co alloy with 5 wt.% Mg, elongated lamellar formations with a transition to parallel strokes are developed on the faces of the octahedron and the cube (Fig. 6). These growth accessories have clear shapes and are crystallographically better decorated than on crystals grown in Fe-Co alloy
[1] F.P. Bundy, H.T. Hall, H.M. Strong, R.H. Wentorf, Man-made diamonds, Nature 176 (1955) 51–55. [2] H.P. Bovenkerk, F.P. Bundy, H.T. Hall, H.M. Strong, R.H. Wentorf, Preparation of diamond, Nature 184 (1959) 1094–1098. [3] H. Kanda, Classification of the catalysts for diamond growth, in: S. Saito, N. Fujimori, O. Fukunaga, M. Kamo, K. Kobashi, M. Yoshikawa (Eds.), Advances in New Diamond Science and Technology, MY, Tokyo, Japan, 1994, pp. 507–512. [4] Y.D. Li, X.P. Jia, B.M. Yan, N. Chen, C. Fang, Y. Li, H.A. Ma, Effects of catalyst height on diamond crystal morphology under high pressure and high temperature, Chin. Phys. B 25 (2016) 048103. [5] W. Han, X.P. Jia, H.S. Jia, M.H. Hu, H.L. Huang, X.B. Liu, H.A. Ma, Effects of Ti additive on HPHT diamond synthesis in Fe-Ni-C system, Chinese Sci. Bull. 54 (2009) 2978–2981. [6] X.B. Liu, X.P. Jia, M. Zhao, H.A. Ma, Diamond crystallization with a carbonyl nickel catalyst under high pressure and temperature, CrystEngComm 18 (2016) 1924–1932. [7] X.B. Liu, H.A. Ma, Z.F. Zhang, M. Zhao, W. Guo, M.H. Hu, G.F. Huang, Y. Li, X.P. Jia, Effects of zinc additive on the HPHT synthesis of diamond in Fe–Ni–C and Fe–C systems, Diamond Relat. Mater. 20 (2011) 468–474. [8] Z.F. Zhang, X.P. Jia, X.B. Liu, M.H. Hu, Y. Li, B.M. Yan, H.A. Ma, Effects of
330
Journal of Crystal Growth 507 (2019) 327–331
T.V. Kovalenko et al.
[9]
[10] [11]
[12]
[13]
[14]
[15]
[16] Y.N. Palyanov, I.N. Kupriyanov, Y.M. Borzdov, A.F. Khokhryakov, N.V. Surovtsev, High-pressure synthesis and characterization of Ge-doped single crystal diamond, Cryst. Growth Des. 16 (2016) 3510–3518. [17] Y. Palyanov, I. Kupriyanov, Y. Borzdov, D. Nechaev, Y. Bataleva, HPHT diamond crystallization in the Mg–Si–C system: effect of Mg/Si composition, Crystals 7 (2017) 119–132. [18] H.M. Strong, R.H. Wentorf, The growth of large diamond crystals, J. Naturwissenschften 59 (1972) 1–7. [19] R.H. Wentorf, Some studies of diamond growth rates, J. Phys. Chem. 75 (1971) 1833–1837. [20] E.Yu. Tonkov, E.G. Ponyatovsky, Phase Transformations of Elements Under High Pressure, CRC Press, LLC, New York, 2005. [21] C. Fernández-Lorenzo, D. Araújo, M. González-Mañas, J. Martín, J. Navas, R. Alcántara, M.P. Villar, D. Bagriantsev, Multi-technique analysis of high quality HPHT diamond crystal, J. Cryst. Growth. 353 (2012) 115–119. [22] A. Haque, P. Pant, J. Narayan, Large-area diamond thin film on Q-carbon coated crystalline sapphire by HFCVD, J. Cryst. Growth. 504 (2018) 17–25. [23] A.M. Zaitsev, Optical Properties of Diamond. Data Handbook, Springer, Berlin, 2010. [24] H. Kanda, T. Ohsawa, O. Fukunaga, I. Sunagawa, Effect of solvent metals upon the morphology of synthetic diamonds, J. Cryst. Growth 94 (1989) 115–124. [25] N. Kubota, M. Yokota, J.W. Mullin, The combined influence of supersaturation and impurity concentration on crystal growth, J. Cryst. Growth 212 (2000) 480–488.
aluminum additive on diamond crystallization in the Fe-Ni-C system under high temperature and high pressure conditions, Sci. China-Phys. Mech. Astron. 55 (2012) 781–785. N.V. Novikov, A.A. Shul’zhenko, The increase of synthetic diamond growth rate, in: S. Saito, O. Fukunaga (Eds.), Science and Technology of New Diamond, Terra Scientific Publishing Company, 1990, pp. 217–219. T.V. Kovalenko, S.A. Ivakhnenko, Properties of diamonds seed-grown in the magnesium-carbon system, J. Superhard Mater. 35 (2013) 3–10. Y.N. Palyanov, Y.M. Borzdov, I.N. Kupriyanov, A.F. Khokhryakov, D.V. Nechaev, Diamond crystallization from an Mg-C system at high pressure high temperature conditions, CrystEngComm 17 (2015) 4928–4936. T.V. Kovalenko, S.A. Ivakhnenko, V.V. Lysakovsky, S.A. Gordeev, A.V. Burchenya, Defect-and-impurity state of diamond single crystals grown in the Fe–Mg–Al–C system, J. Superhard Mater. 39 (2017) 83–87. G.F. Huang, Y.J. Zheng, Z.C. Li, Q. Ga, Effects of Mg on diamond growth and properties in Fe-C system under high pressure and high temperature condition, Chin. Phys. B. 25 (2016) 088104-1–088104-4. A.F. Khokhryakov, A.G. Sokol, Y.M. Borzdov, Y.N. Palyanov, Morphology of diamond crystals grown in magnesium-based systems at high temperatures and high pressures, J. Cryst. Growth 426 (2015) 276–282. Y.N. Palyanov, I.N. Kupriyanov, Y.M. Borzdov, Y.V. Bataleva, High-pressure synthesis and characterization of diamond from an Mg–Si–C system, CrystEngComm 17 (2015) 7323–7331.
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Contents lists available at ScienceDirect
Journal of Crystal Growth journal homepage: www.elsevier.com/locate/jcrysgro
Morphology of diamond single crystals grown in the Fe-Co-Mg-C system a,⁎
a
b
a
T
a
T.V. Kovalenko , V.V. Lysakovskyi , V.M. Kvasnytsya , S.O. Ivakhnenko , O.M. Suprun , A.V. Burcheniaa a b
V. Bakul Institute for Superhard Materials, National Academy of Sciences of Ukraine, str. Avtozavods’ka 2, Kyiv 04074, Ukraine M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences of Ukraine, pr. Palladina 34, Kyiv 03142, Ukraine
A R T I C LE I N FO
A B S T R A C T
Communicated by P. Rudolph
Diamond single crystals in a Fe-Co alloy with addition of 5 and 10 wt.% Mg by temperature gradient method were grown and their morphology was studied. For crystals obtained in the Fe-Co alloy with 5 wt.% Mg, the faces of octahedron, cube, rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} were observed. When the magnesium content in the solvent-alloy increase up to 10 wt.% under the same growth conditions the tetragontrioctahedron {3 1 1} faces on diamond crystals were absent. The topography of diamond crystals faces grown in different systems indicates that octahedron and cube are active growth forms with their growth pyramids, and rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} are forms of passive growth.
Keywords: A1.Crystal morphology A2. Single crystal growth A2. Growth from high temperature solutions B1. Diamond
1. Introduction The study of diamond crystallization in various systems at high pressures and high temperatures is of great interest in connection with the study of mechanisms of nucleation and crystal growth and the possibility of obtaining diamond single crystals with different properties. Most of the researches were carried out in growth systems using solvents based on transition metals (Fe, Co, Ni) [1–8]. Recently considerable attention has been paid to the search for new solvents containing magnesium [9–13]; as it was established earlier in Mg-based systems, it is possible to grow type IIb diamond single crystals, which possess semiconductor properties with growth rates exceeding the growth rates of diamonds in systems based on transition metals in 8–10 times [10]. The first works on the crystallization of diamonds in growth systems with magnesium were carried out in the 1990s [9]. However, the limited possibilities for creating the necessary high pressure and temperature (up to 8.5 GPa and 2200 °C, respectively) did not allow to study of the regularities of boron incorporation into the diamond crystal lattice and the production of semiconductors. In latest years, developed methodological approaches of diamond single crystals growth at extreme pressures and temperatures have allowed studying of regularities of diamond crystallization in magnesium-based systems. Resent studies have shown considerable prospects of these systems in terms of controlled doping of diamond with boron and nitrogen in the growth process. Diamond crystals grown in magnesium-based systems, in addition to semiconductor properties and extremely high growth
⁎
rates, have a number of unique features such as extraordinary microand macro-morphology, internal structure [14]. The morphology of diamond single crystals grown in Mg-based systems is different and depends significantly on the composition of the growth system [14–16]. There are two main habit types – cubic and cube-octahedron. The faces of the {1 1 1} and {1 0 0} are the main faces for crystals grown in Mg-Cu-C, Mg-Ni-C, Mg-Cu-Ni-C, Mg-Ag-Ni-C systems at a pressure of 6.3 GPa and a temperature of 1550–1650 °C [16]; at a magnesium content of 40–45 at.% crystal growth occurs under conditions of suppression of the {1 0 0} faces and the formation of antiscale crystal. The faces of the tetragon-trioctahedron {3 1 1} are formed when the faces {1 1 1} and {1 0 0} are completely wedged out; a decreasing of magnesium content in such systems and an increasing of growing temperature lead to reduce facial suppression. In the Mg-Si-C system [17] with silicon content of 1 wt.%, approximately the same development of the {1 0 0} and {1 1 1} faces and the growth of the cube-octahedral crystals are observed. When ≥2 wt.% Si is added to the growth system morphology of crystals is determined by the dominant {1 1 1} faces. In order to obtain information on the diamond crystallization in magnesium-based systems, Fe-Co-Mg-C system with different magnesium content was investigated. Experiments were carried out using alloys-solvents based on Fe-Co with 5 wt.% Mg and 10 wt.% Mg at a pressure of 6.0–6.5 GPa and a temperature of 1420–1500 °C.
Corresponding author. E-mail address: [email protected] (T.V. Kovalenko).
https://doi.org/10.1016/j.jcrysgro.2018.11.040 Received 18 October 2018; Received in revised form 29 November 2018; Accepted 30 November 2018 Available online 01 December 2018 0022-0248/ © 2018 Elsevier B.V. All rights reserved.
Journal of Crystal Growth 507 (2019) 327–331
T.V. Kovalenko et al.
Fig. 1. X-ray picture of diamond single crystal grown in Fe-Co allow with 10 wt. % Mg.
Fig. 2. Raman spectra of diamond single crystals grown in Fe-Co alloy with 5 wt.% Mg (1) and 10 wt.% Mg (2).
Fig. 3. SEM images of diamond single crystals (o-octahedron, c-cube, t-tetragon-trioctahedron {3 1 1}, r-rhomb-dodecahedron) obtained in the Fe-Co-MgC system. (a) Fe-Co alloy with 10 wt.% Mg (mass 0.12 ct); (b, c) – Fe-Co alloy with 5 wt.% Mg (0.17 and 0.13 ct).
2. Experiment The experiments were carried out at high pressure and high temperature in large volume cubic high pressure apparatus 6 × 2.8·104 MN. A cubic container with dimensions of 58 × 58 × 58 mm was used. Fe-Co alloy, graphite GSM1 and Mg purity 99.99 with a fraction of 30–40 μm were used in the experiments. Graphite and Mg were mixed thoroughly for 2 h. Then the mixed powder was pre-pressed into a disk at a pressure 0.15 GPa. The Mg additives used in the experiments were 5 wt.% and 10 wt.%. The growing process was carried out by the temperature gradient method [18,19], at a pressure in the range of 6.0–6.5 GPa and a temperature of 1420–1500 °C. The pressure was calibrated by the pressure induced phase transitions of bismuth and thallium [20]. The temperature was measured by the PtRh30/PtRh6 thermocouple. The accuracy values of the pressure and temperature measurement was ± (0.2 ÷ 0.4) GPa and ± (40 ÷ 60) °C, respectively. After the HPHT experiments metal solvent and graphite were removed by boiling the sample in acid. The X-ray diffraction (XRD) was performed using DRON x-ray diffractometer with CuKα x-ray source. Raman spectra were obtained with using a triple Raman spectrometer T-64000 Horiba Jobin-Yvon, equipped with electrically cooled CCD detector. The excitation of the
Fig. 4. An idealized image of a diamond single crystal obtained in a Fe-Co alloy with 5 wt.% Mg.
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Journal of Crystal Growth 507 (2019) 327–331
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Fig. 5. An idealized image of a diamond single crystal obtained in a Fe-Co alloy with 10 wt.% Mg. Fig. 6. Topography of diamond single crystals faces grown in the Fe-Co alloy with 5 wt.% Mg. (a and b) – the faces of the {1 1 1} and {1 0 0} forms have clear elongated lamellar formations with a transition to parallel strokes, (c and d) the faces of the {1 1 0} and {3 1 1} forms ornamented with parallel strokes along the octahedron plane.
Fig. 3 shows diamond crystals obtained in the Fe-Co-Mg-C system with different magnesium content grown by temperature gradient method with growth rates ∼4–5 mg/h. Crystals grown in the Fe-Co alloy with 5 wt.% Mg have the following set of simple forms {1 1 1}–{1 0 0}–{1 1 0}–{3 1 1} (Figs. 3 and 4); the cube and octahedron faces are developed on all crystals. The rhomb-dodecahedron often has an incomplete development, whereas the tetragon-trioctahedron {3 1 1} is almost always full. Usually the octahedron faces dominate on crystals: the ratio of the areas of the octahedron and cube faces is approximately 3: 1 (∼65 ÷ 85% and ∼15 ÷ 35%, respectively). The boundaries of the rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} are present in the form of blunt ribs between the edges of the octahedron and the cube. A set of simple crystal forms and their development in single crystals obtained in the Fe-Co alloy with 10 wt.% Mg (Figs. 3 and 5) vary depending on the growing conditions. A cube-octahedral crystal was grown at the maximum temperature (Fig. 5a); in other cases, at a lower temperature, cubo-octahedral faces with poorly developed rhomb-dodecahedron facets were observed, and the rhomb-dodecahedron is usually incomplete. Unlike the idealized images of diamond crystals (Figs. 4 and 5), the faces of different shapes of their real crystals have different development (Fig. 3). The faces of the octahedron are dominated, further,
Raman scattering was performed by a 532 nm diode-pumped solid-state laser. The surface morphologies were examined with an optical microscope (OM), a goniometer GD-1, and a scanning electron microscope (SEM). 3. Results and discussion XRD and Raman spectroscopy are very effective technique to characterize diamond crystals [21]. Fig. 1 represents a typical X-ray diffraction pattern obtained from diamond single crystal grown in the Fe-Co alloy with 10 wt.% Mg. All crystals grown in Fe-Co-Mg-C system with different magnesium content have similar XRD picture. XRD spectrum shows characteristic diamond peaks at (2θ) 43.93° and 75.37 corresponding to diamond {1 1 1} and {2 2 0} reflections, respectively [22]. Raman spectroscopy was used to characterize the diamond crystal grown in Fe-Co-Mg-C system (Fig. 2). The Raman peaks values and FWHM (full width at half maximum) indicate the relative quality of obtained crystals [23]. All diamonds grown in Fe-Co-Mg-C system with different magnesium content display a sharp band at 1332.5 cm−1. FWHM is observed to be very low (3.2 cm−1), that indicate the good crystalline quality of crystals. 329
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with 10 wt.% Mg (Fig. 7). On the octahedron faces, sets of plates at an angle of 60° relative to one another are observed. The boundaries of the rhomb-dodecahedron and some faces of the tetragon-trioctahedron {3 1 1} are ornamented by parallel strokes along the (1 1 1) plane, which indicates their passive growth. The results of topographic researches indicate that the crystals in both systems grew layer by layer (1 1 1) and (1 0 0), with the predominant development of the (1 1 1) planes. This is because the octahedron and the cube have different own growth pyramids. The faces of the rhomb-dodecahedron and tetragon-trioctahedron {3 1 1} apparently do not have their own growth pyramids and are formed by the degeneration of the faces of the octahedron and the cube. There are no signs of spiral growth of the octahedron and cube faces. Draws attention to the fact that the reliefs of the octahedron and the cube faces for crystals obtained in solvents with different Mg content (5 and 10 wt.%, Figs. 4 and 5, respectively) significantly differ from each other. The faces of the octahedron and the cube (Fig. 7) are covered by differently sized and shaped subparallel-oriented lamellar figures, while the faces of the rhomb-dodecahedron are ornamented by parallel strokes along the (1 1 1) plane. At high magnifications, both growth and dissolution sculptures are fixed. On the octahedron faces, patterns of triangular and hexagonal cavities typical for diamond crystals are observed; sculptures of polycentric and dendritic growth are also present; on the cube faces patterns of quadrangular cavities and sculptures of dendritic growth are observed. Cavities on the faces of the octahedron reveal a very thin layering along (1 1 1). 4. Conclusions 1. Increasing of magnesium content in the growth system based on FeCo from 5 to 10 wt.% leads to a change in the degree of diamond single crystals faces development; for crystals obtained with a large magnesium content, the tetragon-trioctahedron faces {3 1 1} are wedged out. 2. Apparently, increasing of magnesium content in the growth system stabilizes the growth of the octahedron and the cube faces, slowing their growth and contributing to their area development. 3. Microrelief of diamond single crystals faces grown in the Fe-CoMg–C system indicate layerwise growth mechanism with generation of faces at both edges and vertices, and polycentrically. Appendix A. Supplementary material Supplementary data to this article can be found online at https:// doi.org/10.1016/j.jcrysgro.2018.11.040.
Fig. 7. Topography of the faces of various forms of diamond single crystals grown in the Fe-Co alloy with 10 wt.% Mg, on which {3 1 1} faces are absent.
References according to the degree of development, a cube, tetragon-trioctahedron {3 1 1} are presented, faces of the rhomb-dodecahedron are less developed. It should be noted that the increasing of magnesium content in the growth system based on Fe-Co from 5 to 10 wt.% leads to a change in the degree of diamond single crystals faces development; for crystals obtained with a large magnesium content, the tetragon-trioctahedron faces {3 1 1} are wedged out. Increasing of magnesium content in the growth system leads to a change in the surface energy of the crystal and, accordingly, to the formation of the equilibrium form of the crystal formed by planar faces [24,25]. The topography of the faces of crystals grown in the Fe-Co-Mg–C system was studied. For crystals grown in Fe-Co alloy with 5 wt.% Mg, elongated lamellar formations with a transition to parallel strokes are developed on the faces of the octahedron and the cube (Fig. 6). These growth accessories have clear shapes and are crystallographically better decorated than on crystals grown in Fe-Co alloy
[1] F.P. Bundy, H.T. Hall, H.M. Strong, R.H. Wentorf, Man-made diamonds, Nature 176 (1955) 51–55. [2] H.P. Bovenkerk, F.P. Bundy, H.T. Hall, H.M. Strong, R.H. Wentorf, Preparation of diamond, Nature 184 (1959) 1094–1098. [3] H. Kanda, Classification of the catalysts for diamond growth, in: S. Saito, N. Fujimori, O. Fukunaga, M. Kamo, K. Kobashi, M. Yoshikawa (Eds.), Advances in New Diamond Science and Technology, MY, Tokyo, Japan, 1994, pp. 507–512. [4] Y.D. Li, X.P. Jia, B.M. Yan, N. Chen, C. Fang, Y. Li, H.A. Ma, Effects of catalyst height on diamond crystal morphology under high pressure and high temperature, Chin. Phys. B 25 (2016) 048103. [5] W. Han, X.P. Jia, H.S. Jia, M.H. Hu, H.L. Huang, X.B. Liu, H.A. Ma, Effects of Ti additive on HPHT diamond synthesis in Fe-Ni-C system, Chinese Sci. Bull. 54 (2009) 2978–2981. [6] X.B. Liu, X.P. Jia, M. Zhao, H.A. Ma, Diamond crystallization with a carbonyl nickel catalyst under high pressure and temperature, CrystEngComm 18 (2016) 1924–1932. [7] X.B. Liu, H.A. Ma, Z.F. Zhang, M. Zhao, W. Guo, M.H. Hu, G.F. Huang, Y. Li, X.P. Jia, Effects of zinc additive on the HPHT synthesis of diamond in Fe–Ni–C and Fe–C systems, Diamond Relat. Mater. 20 (2011) 468–474. [8] Z.F. Zhang, X.P. Jia, X.B. Liu, M.H. Hu, Y. Li, B.M. Yan, H.A. Ma, Effects of
330
Journal of Crystal Growth 507 (2019) 327–331
T.V. Kovalenko et al.
[9]
[10] [11]
[12]
[13]
[14]
[15]
[16] Y.N. Palyanov, I.N. Kupriyanov, Y.M. Borzdov, A.F. Khokhryakov, N.V. Surovtsev, High-pressure synthesis and characterization of Ge-doped single crystal diamond, Cryst. Growth Des. 16 (2016) 3510–3518. [17] Y. Palyanov, I. Kupriyanov, Y. Borzdov, D. Nechaev, Y. Bataleva, HPHT diamond crystallization in the Mg–Si–C system: effect of Mg/Si composition, Crystals 7 (2017) 119–132. [18] H.M. Strong, R.H. Wentorf, The growth of large diamond crystals, J. Naturwissenschften 59 (1972) 1–7. [19] R.H. Wentorf, Some studies of diamond growth rates, J. Phys. Chem. 75 (1971) 1833–1837. [20] E.Yu. Tonkov, E.G. Ponyatovsky, Phase Transformations of Elements Under High Pressure, CRC Press, LLC, New York, 2005. [21] C. Fernández-Lorenzo, D. Araújo, M. González-Mañas, J. Martín, J. Navas, R. Alcántara, M.P. Villar, D. Bagriantsev, Multi-technique analysis of high quality HPHT diamond crystal, J. Cryst. Growth. 353 (2012) 115–119. [22] A. Haque, P. Pant, J. Narayan, Large-area diamond thin film on Q-carbon coated crystalline sapphire by HFCVD, J. Cryst. Growth. 504 (2018) 17–25. [23] A.M. Zaitsev, Optical Properties of Diamond. Data Handbook, Springer, Berlin, 2010. [24] H. Kanda, T. Ohsawa, O. Fukunaga, I. Sunagawa, Effect of solvent metals upon the morphology of synthetic diamonds, J. Cryst. Growth 94 (1989) 115–124. [25] N. Kubota, M. Yokota, J.W. Mullin, The combined influence of supersaturation and impurity concentration on crystal growth, J. Cryst. Growth 212 (2000) 480–488.
aluminum additive on diamond crystallization in the Fe-Ni-C system under high temperature and high pressure conditions, Sci. China-Phys. Mech. Astron. 55 (2012) 781–785. N.V. Novikov, A.A. Shul’zhenko, The increase of synthetic diamond growth rate, in: S. Saito, O. Fukunaga (Eds.), Science and Technology of New Diamond, Terra Scientific Publishing Company, 1990, pp. 217–219. T.V. Kovalenko, S.A. Ivakhnenko, Properties of diamonds seed-grown in the magnesium-carbon system, J. Superhard Mater. 35 (2013) 3–10. Y.N. Palyanov, Y.M. Borzdov, I.N. Kupriyanov, A.F. Khokhryakov, D.V. Nechaev, Diamond crystallization from an Mg-C system at high pressure high temperature conditions, CrystEngComm 17 (2015) 4928–4936. T.V. Kovalenko, S.A. Ivakhnenko, V.V. Lysakovsky, S.A. Gordeev, A.V. Burchenya, Defect-and-impurity state of diamond single crystals grown in the Fe–Mg–Al–C system, J. Superhard Mater. 39 (2017) 83–87. G.F. Huang, Y.J. Zheng, Z.C. Li, Q. Ga, Effects of Mg on diamond growth and properties in Fe-C system under high pressure and high temperature condition, Chin. Phys. B. 25 (2016) 088104-1–088104-4. A.F. Khokhryakov, A.G. Sokol, Y.M. Borzdov, Y.N. Palyanov, Morphology of diamond crystals grown in magnesium-based systems at high temperatures and high pressures, J. Cryst. Growth 426 (2015) 276–282. Y.N. Palyanov, I.N. Kupriyanov, Y.M. Borzdov, Y.V. Bataleva, High-pressure synthesis and characterization of diamond from an Mg–Si–C system, CrystEngComm 17 (2015) 7323–7331.
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