- Email: [email protected]
Growth of cadmium mercury thiocyanate dimethylsulphoxide single crystal for laser frequency doubling
Progress in Crystal Growth and Characterization of Materials
Progress in Crystal Growth and Characterization of Materials (2000) 75-79 http://www.elsevier.com/locate/pcrysgrow
PERGAMON
GROWTH OF CADMIUM MERCURY THIOCYANATE DIMETHYLSULPHOXIDE SINGLE CRYSTAL FOR LASER FREQUENCY DOUBLING
Shiyi Guo, DuorongYuan, Dong Xu, GuanghuiZhang,Suoying Sun, Fanqing Meng, XinqiangWang, XueningJiang, Minhua Jiang Institute of Crystal Materials, ShandongUniversity,Jinan250100, P. R. China E-mail: [email protected]
Daliang Sun, Xiling Yu State Laboratory of CrystalMaterials, ShandongUniversity,Jinan250100, P. R. China ABSTRACT This paper reports the growth of an organometallic nonlinear optical (NLO) complex crystal, Cadmium mercury thiocyanate dimethyl-sulphoxide (CdHg(SCN)4(H6C2OS)2, CMTD), which was grown from aqueous solution by a temperature lowering method. Its powder SHG intensity is higher than that of CMTC. The crystal size of CMTD can reach 25x23× 15mm3. The solubility curve, and solubility variation with pH value are also reported. The growth habits of crystals of CMTD grown under different conditions are discussed and the optimized condition for the growth CMTD using a temperature-lowering method from aqueous solution are also discussed. Keywords: Growth of CMTD single crystal, Solution temperature-lowering method, solubility curve INTRODUCTION Nonlinear optical (NLO) materials play an important role in many fields of scientific applications. Organometallic complexes provid an important source of new NLO materials[i]. In recent years, it has attracted the attention world-wide of scientists for its chemical stability, high nonlinearity and good transmission in visible waveband. By following the concepts of the double radical structure model theory, many organometallie complex crystals have been identified and grown as good nonlinear optical materials• Developments in semiconductor materials in recent years have resulted in stable blue-light LED's. But stable output of violet light still can not be obtained. In order to obtain a stable output of violet-light which can be used to generate information storage, we have carried out research studies to explore these materials, especially in the form of crystals[2]. Crystal-line CMTD is one of these materials. It belongs to the orthorhombic system, space group P21212v Its lattice parameters are respectively: a= 8.5188(6) A, b=8.5398(7) A, c=28.224(6) A, V=2053.3(5) A 3, Z=4 and Dm=2.270 g/cm3. In this paper, we report on the growth of CMTD crystals under optimized conditions by using a temperature-lowering method from aqueous solution. EXPERIMENTS 1. Crystal growth Crystals of CMTD were prepared by using dimethyl sulphoxide as a ligand to react with Cadmium mercury thiocyanate (CMTC) in a mixture of dimethyl sulphoxide and deionized water• The chemical equation is given as follows: 0960-8974/00/$ - see front matter © 2000 Published by Elsevier Science Ltd. PlI: S0960-8974(00)00019-X
76
Shiyi Guo et al. /Prog. Crystal Growth and Charact. 40 (2000) 75-79
CdHg(SCN)4 +
2(CH3):S(Y--~CdHg(SCN),o2(CH3):SO
The solubility of CMTD crystals in a mixture of dimethyl sulphoxide and deionized water (2: I V/V), was measured using a schlieren method. The solubility curve is shown in fig. 1. The temperature dependence of the solubility was fitted to the following equation: S=a+bt
2°t ............
]
'°t G0-
40-
20-
Temperature(~C) Fig. 1 The solubility curve of CMTD crystal
where the fitting parameters are a = -65.62517, b = 3.55997, and t is the temperature in °C. Small single crystals can be crystallized by spontaneous nucleation in a saturated solution made of CMTC as raw material dissolve in a mixture of analytical trade reagent dimethyl sulphoxide and de-ionized water (volume ratio 3:1). A small single crystal without macrodefects was selected as a seed so that fast good quality crystal growth could be achieved. The growth temperature was varied from 43-22°C. At the beginning, because the seed is very small, the temperature-lowering rate should be slower (0.05°C/day), after a period, it can be progressively increased. The precision of temperature control is +0.01°C, the crystal rotation rate is 30revs./min and linear growth rate is 0.5ram/day. Under these conditions, within 45 days, a colorless, high optical quality single crystal with size 25X23× 15 mm 3 can be obtained. Fig. 2 shows an asgrown CMTD crystal with size 25X 23)< 15 mm 3.
Fig.2. The as-grown CMTD crystal 2. Crystal structure The crystal structure of CMTD was determined for the first time using a four-circle refractometer at
77
Shiyi Guo et al. / Prog. Crystal Growth and Charact. 40 (2000) 75-79
room temperature. The crystal belongs to the orthorhombic system, space g~-oup P2~2~2v Its lattice parameters are respectively: a= 8.5188(6) A, b~8.5398(7)iA, c=28.224(6) A, V~-2053.3(5) A~,' Z=4 and Dm=2.270 g/cm3. The X-ray diffraction data of CMTD was collected. The X-ray diffraction graph of CMTD crystal is shown in fig.3.
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~: ~
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t'
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1 I
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{
t
I
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l
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Fig.3. The X-ray diffraction graph of CMTD crystal The data of X,ra" diffraction of the crystal calculated and measured are listed in table 1. 0
do~. (A)
do+).(A)
hkl
lo~s
12.506
7.069
7.05625
004
I00
15.935
5.559
5.54601
1 12
71.3
18.804
4.716
4.70919
0 15
17.3
20.803
4.267
4.27000
020
21.7
23.941
3.713
3.70931
1 16
29.0
24.399
3.645
3.64616
0 17
15.1
25.187
3,533
3.53277
2 13
24,5
32.263
2,772
2.77209
12 7
19.0
32.913
2.719
2.71854
303
13.2
33.807
2.649
2.64679
3 12
20.5
35,071
2.556
2.55641
1 1 10
18.6
39.283
2.291
2,29235
228
13.8
I
I
1
I
I
I
I
I
I
78
Shiyi Guo et aL / Prog. Crystal Growth and Charact. 40 (2000) 75-79
DISCUSSION The crystal habit of CMTD crystals grown in solutions with different pH value were studied by using an optical microscope. Fig.4a shows the crystallization in pure CMTD solution with a pH value of 5. The crystal size is small and the shape of some crystals is irregular. Fig. 4b shows the results of crystallization in CMTD solution with a pH value of 6, which was adjusted by KOH solution, and Fig. 4c, d, e, falso shows the results of crystallization in CMTD solution with a pH value of 1, 2, 3, 4 respectively, which pH values were Changed using HC1 solution. Comparing them with each other, we found that when the pH value of the solution is 3-4, the crystal shape is cubic and easy to crystallize in large size.
Fig.4. Photographs of microcrystal of CMTD grown in solutions of different pH value a, pH=5;
b, pH=6;
9ot
i
c, pH=l;
•
I
d, pH=2; e, pH=3;
•
!
|
f, pHi4
i
8O
.0
70-
s
0
60-
5O
pH value Fig.5 Solubilityvariationof CMTD with the pH value
Shiyi Guo et aL / Prog. Crystal Growth and Charact. 40 (2000) 75-79
79
The solubility of CMTD can also be affected by the pH value of the solution. The solubility decreased very quickly with increase in pH value. Figure 5 shows the solubility variation with pH value. This can be explained by formulation of the chemical equations and the fact that the solubilities of CdHg(SCN)sCI((CH3)zSO)2 and CdHg(SCN)2C12((CH3)2SO)2 in solution are larger than that of CMTD, Note [Cl-]oc[H-], hence an increase [CF] represents an increase in acidity and a decrease in pH. CdHg(SCN)4((CH3)2SO)2 + el- <=>CdHg(SCN)3el((Cg3)2SO)2 + SCNCdHg(SCN)3CI((CH3)2SO)2 + el- ¢:> CdHg(SCN)2CI=((CH3)2SO)2 + SeNConsidering the influence of the pH value on crystalline habit, we take 3-4 as the optimum pH value of the solution for the CMTD crystal growth. CONCLUSSION In summary, the pH value is an important factor for the crystal growth of CMTD, the pH value can change the shape and the solubility of CMTD crystals. Large crystal CMTD crystals with good optical quality can be obtained under optimum conditions. ACKNOWLEDGEMENT This work is supported by NSFC, No. 69890230 and No. 59823003. REFERENCES 1, M. H. Jiang, D. Xu, G. C. Xing and Z. S. Shao, Synthetic Crystals, 3-4, 1 (1985). 2. Yuan D. R., Xu D., Liu M. G., Fang Q., Yu W. T., Hou W. B., Bing Y. H , Sun S. Y., Jiang M. H., Applied Physics Letters 70, 544 (1997).
Progress in Crystal Growth and Characterization of Materials (2000) 75-79 http://www.elsevier.com/locate/pcrysgrow
PERGAMON
GROWTH OF CADMIUM MERCURY THIOCYANATE DIMETHYLSULPHOXIDE SINGLE CRYSTAL FOR LASER FREQUENCY DOUBLING
Shiyi Guo, DuorongYuan, Dong Xu, GuanghuiZhang,Suoying Sun, Fanqing Meng, XinqiangWang, XueningJiang, Minhua Jiang Institute of Crystal Materials, ShandongUniversity,Jinan250100, P. R. China E-mail: [email protected]
Daliang Sun, Xiling Yu State Laboratory of CrystalMaterials, ShandongUniversity,Jinan250100, P. R. China ABSTRACT This paper reports the growth of an organometallic nonlinear optical (NLO) complex crystal, Cadmium mercury thiocyanate dimethyl-sulphoxide (CdHg(SCN)4(H6C2OS)2, CMTD), which was grown from aqueous solution by a temperature lowering method. Its powder SHG intensity is higher than that of CMTC. The crystal size of CMTD can reach 25x23× 15mm3. The solubility curve, and solubility variation with pH value are also reported. The growth habits of crystals of CMTD grown under different conditions are discussed and the optimized condition for the growth CMTD using a temperature-lowering method from aqueous solution are also discussed. Keywords: Growth of CMTD single crystal, Solution temperature-lowering method, solubility curve INTRODUCTION Nonlinear optical (NLO) materials play an important role in many fields of scientific applications. Organometallic complexes provid an important source of new NLO materials[i]. In recent years, it has attracted the attention world-wide of scientists for its chemical stability, high nonlinearity and good transmission in visible waveband. By following the concepts of the double radical structure model theory, many organometallie complex crystals have been identified and grown as good nonlinear optical materials• Developments in semiconductor materials in recent years have resulted in stable blue-light LED's. But stable output of violet light still can not be obtained. In order to obtain a stable output of violet-light which can be used to generate information storage, we have carried out research studies to explore these materials, especially in the form of crystals[2]. Crystal-line CMTD is one of these materials. It belongs to the orthorhombic system, space group P21212v Its lattice parameters are respectively: a= 8.5188(6) A, b=8.5398(7) A, c=28.224(6) A, V=2053.3(5) A 3, Z=4 and Dm=2.270 g/cm3. In this paper, we report on the growth of CMTD crystals under optimized conditions by using a temperature-lowering method from aqueous solution. EXPERIMENTS 1. Crystal growth Crystals of CMTD were prepared by using dimethyl sulphoxide as a ligand to react with Cadmium mercury thiocyanate (CMTC) in a mixture of dimethyl sulphoxide and deionized water• The chemical equation is given as follows: 0960-8974/00/$ - see front matter © 2000 Published by Elsevier Science Ltd. PlI: S0960-8974(00)00019-X
76
Shiyi Guo et al. /Prog. Crystal Growth and Charact. 40 (2000) 75-79
CdHg(SCN)4 +
2(CH3):S(Y--~CdHg(SCN),o2(CH3):SO
The solubility of CMTD crystals in a mixture of dimethyl sulphoxide and deionized water (2: I V/V), was measured using a schlieren method. The solubility curve is shown in fig. 1. The temperature dependence of the solubility was fitted to the following equation: S=a+bt
2°t ............
]
'°t G0-
40-
20-
Temperature(~C) Fig. 1 The solubility curve of CMTD crystal
where the fitting parameters are a = -65.62517, b = 3.55997, and t is the temperature in °C. Small single crystals can be crystallized by spontaneous nucleation in a saturated solution made of CMTC as raw material dissolve in a mixture of analytical trade reagent dimethyl sulphoxide and de-ionized water (volume ratio 3:1). A small single crystal without macrodefects was selected as a seed so that fast good quality crystal growth could be achieved. The growth temperature was varied from 43-22°C. At the beginning, because the seed is very small, the temperature-lowering rate should be slower (0.05°C/day), after a period, it can be progressively increased. The precision of temperature control is +0.01°C, the crystal rotation rate is 30revs./min and linear growth rate is 0.5ram/day. Under these conditions, within 45 days, a colorless, high optical quality single crystal with size 25X23× 15 mm 3 can be obtained. Fig. 2 shows an asgrown CMTD crystal with size 25X 23)< 15 mm 3.
Fig.2. The as-grown CMTD crystal 2. Crystal structure The crystal structure of CMTD was determined for the first time using a four-circle refractometer at
77
Shiyi Guo et al. / Prog. Crystal Growth and Charact. 40 (2000) 75-79
room temperature. The crystal belongs to the orthorhombic system, space g~-oup P2~2~2v Its lattice parameters are respectively: a= 8.5188(6) A, b~8.5398(7)iA, c=28.224(6) A, V~-2053.3(5) A~,' Z=4 and Dm=2.270 g/cm3. The X-ray diffraction data of CMTD was collected. The X-ray diffraction graph of CMTD crystal is shown in fig.3.
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~: ~
tI
t'
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% 1 I
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Fig.3. The X-ray diffraction graph of CMTD crystal The data of X,ra" diffraction of the crystal calculated and measured are listed in table 1. 0
do~. (A)
do+).(A)
hkl
lo~s
12.506
7.069
7.05625
004
I00
15.935
5.559
5.54601
1 12
71.3
18.804
4.716
4.70919
0 15
17.3
20.803
4.267
4.27000
020
21.7
23.941
3.713
3.70931
1 16
29.0
24.399
3.645
3.64616
0 17
15.1
25.187
3,533
3.53277
2 13
24,5
32.263
2,772
2.77209
12 7
19.0
32.913
2.719
2.71854
303
13.2
33.807
2.649
2.64679
3 12
20.5
35,071
2.556
2.55641
1 1 10
18.6
39.283
2.291
2,29235
228
13.8
I
I
1
I
I
I
I
I
I
78
Shiyi Guo et aL / Prog. Crystal Growth and Charact. 40 (2000) 75-79
DISCUSSION The crystal habit of CMTD crystals grown in solutions with different pH value were studied by using an optical microscope. Fig.4a shows the crystallization in pure CMTD solution with a pH value of 5. The crystal size is small and the shape of some crystals is irregular. Fig. 4b shows the results of crystallization in CMTD solution with a pH value of 6, which was adjusted by KOH solution, and Fig. 4c, d, e, falso shows the results of crystallization in CMTD solution with a pH value of 1, 2, 3, 4 respectively, which pH values were Changed using HC1 solution. Comparing them with each other, we found that when the pH value of the solution is 3-4, the crystal shape is cubic and easy to crystallize in large size.
Fig.4. Photographs of microcrystal of CMTD grown in solutions of different pH value a, pH=5;
b, pH=6;
9ot
i
c, pH=l;
•
I
d, pH=2; e, pH=3;
•
!
|
f, pHi4
i
8O
.0
70-
s
0
60-
5O
pH value Fig.5 Solubilityvariationof CMTD with the pH value
Shiyi Guo et aL / Prog. Crystal Growth and Charact. 40 (2000) 75-79
79
The solubility of CMTD can also be affected by the pH value of the solution. The solubility decreased very quickly with increase in pH value. Figure 5 shows the solubility variation with pH value. This can be explained by formulation of the chemical equations and the fact that the solubilities of CdHg(SCN)sCI((CH3)zSO)2 and CdHg(SCN)2C12((CH3)2SO)2 in solution are larger than that of CMTD, Note [Cl-]oc[H-], hence an increase [CF] represents an increase in acidity and a decrease in pH. CdHg(SCN)4((CH3)2SO)2 + el- <=>CdHg(SCN)3el((Cg3)2SO)2 + SCNCdHg(SCN)3CI((CH3)2SO)2 + el- ¢:> CdHg(SCN)2CI=((CH3)2SO)2 + SeNConsidering the influence of the pH value on crystalline habit, we take 3-4 as the optimum pH value of the solution for the CMTD crystal growth. CONCLUSSION In summary, the pH value is an important factor for the crystal growth of CMTD, the pH value can change the shape and the solubility of CMTD crystals. Large crystal CMTD crystals with good optical quality can be obtained under optimum conditions. ACKNOWLEDGEMENT This work is supported by NSFC, No. 69890230 and No. 59823003. REFERENCES 1, M. H. Jiang, D. Xu, G. C. Xing and Z. S. Shao, Synthetic Crystals, 3-4, 1 (1985). 2. Yuan D. R., Xu D., Liu M. G., Fang Q., Yu W. T., Hou W. B., Bing Y. H , Sun S. Y., Jiang M. H., Applied Physics Letters 70, 544 (1997).