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Electron paramagnetic resonance in deuterated nickel fluosilicate
Solid State Communications, Printed in Great Britain.
Vol. 42, No. 5, pp. i-v,
1982.
Abstracts of Articles to be Published in The Journal of Physics and Chemistry of Solids ‘J Phys. Chem. Solids (to be published)
should be cited
in references to material quoted from this section prior to the publication of the relevant article.
1.
EFFECT OF BORON ON ORDER-DISORDER TRANSFORMATION OF SOME HEATTREATED Cu-Ni-Zn-Mn ALLOYS Mohamed I. Simail, Dep. Che,. Eng., Univ. Waterloo, Waterloo, Ont., Canada; and Ahmed S.A. Ammar, Dep. Math. Phys., Fat. Eng. Alexandria Univ., Alex., Egypt.
Atomic ordering of the alloy C~,.,,NiZn,~,,Mne_-,r~ was studied for different heat-treatment conditions. The effect of addition of boron (O-l at.%) on the orderdisorder transformation was tested. Heat capacity measurement techniques were used to follow the progress of the solid state order-disorder transformation. The C, values were measured during cooling or heating of heat treated specimens (3 hr, 1073 K) using a PerkinElmer DSC-2 calorimeter, The experimental results show that there exists a minimum and/or a maximum in the specific heat curve, C,(r) vs T. These critical values (min. or max. C,), together with the temperature ranges in which the solid state transformations (order/disorder) occur, depend on both the heat-treatment and the boron content of the alloy. Received 22 January 198 1 2.
SPECTRAL DEPENDENCE OF PHOTORESPONSE AND ELECTRONIC STRUCTURE OF MONOCRYSTAL OF CuInTe, N.V. Joshi & Ht Aguilar, Department0 de Fiscia, Universidad de Los Andes, MCrida, venezuala.
The photoconductivity spectrum of a single crystal of the semiconducting compound CuInTe, has been experimentally resolved into various distinct peaks at 300 K in the range - from 0.5 p to 1.5 p for the first time. The observed peaks are explained on the basis of the transitions originating - from the valence sub-band structure. Impurity level is also reflected in the photoconductivity spectrum. Received 22 June 198 1
3.
ELECTRON PARAMAGNETIC RESONANCE IN DEUTERATED NICKEL FLUOSILICATE R.S. Rubins and Talatnaz Haghighatjou, Department of Physics, BoxNo. 19059, The University of Texas at Arlington, Arlington, TX 76019, U.S.A.
Electron paramagnetic resonance measurements in single crystals of NiSiF6 - 6Ds 0 were made at K, Ku and Ka bands at 4.2 K and between 77 and 300 K. The measuredg values were in the range 2.23-2.26, while the zero-field splitting parameter D varied from - (0.185 + 0.005) cm-’ at 4.2 K to - (0.53 f 0.01) cm-’ at 298 K. The parameters of the trimolecular hexagonal unit cell were determined to be approximately a = 9.28 A, C = 9.58 A from powder X-ray diffraction measurements at room temperature. Received 29 June 1981 4.
AN INTERPRETATION OF STRUCTURAL SORTING DIAGRAMS FOR AB TYPE COMPOUNDS USING MOLECULAR ORBITAL IDEAS Jeremy K. Burdett and Sarah L. Price, Department of Chemistry, The University of Chicago, Chicago, Il60637, U.S.A.
The factors governing the structure adopted by a particular AB compound are investigated by deriving two parameters reflecting aspects of the interaction between A and B, using simple molecular orbital ideas, which can be quantified bu use of atomic parameters derived from pseudopotential theory. A plot of the values of these two parameters, for a large database of compounds, produces a remarkable topological clustering of AB compounds with the same structure. This structural sorting can also be effected for nonoctet AB compounds if the number of electrons is taken into account. These parameters are related to other indices, Ro, R,, previously used by Bloch, Zunger, Phillips and coworkers to construct structural sorting diagrams. Hence we find a justification for the success of such displays, and shed light on the reasons underpinning structural
Vol. 42, No. 5, pp. i-v,
1982.
Abstracts of Articles to be Published in The Journal of Physics and Chemistry of Solids ‘J Phys. Chem. Solids (to be published)
should be cited
in references to material quoted from this section prior to the publication of the relevant article.
1.
EFFECT OF BORON ON ORDER-DISORDER TRANSFORMATION OF SOME HEATTREATED Cu-Ni-Zn-Mn ALLOYS Mohamed I. Simail, Dep. Che,. Eng., Univ. Waterloo, Waterloo, Ont., Canada; and Ahmed S.A. Ammar, Dep. Math. Phys., Fat. Eng. Alexandria Univ., Alex., Egypt.
Atomic ordering of the alloy C~,.,,NiZn,~,,Mne_-,r~ was studied for different heat-treatment conditions. The effect of addition of boron (O-l at.%) on the orderdisorder transformation was tested. Heat capacity measurement techniques were used to follow the progress of the solid state order-disorder transformation. The C, values were measured during cooling or heating of heat treated specimens (3 hr, 1073 K) using a PerkinElmer DSC-2 calorimeter, The experimental results show that there exists a minimum and/or a maximum in the specific heat curve, C,(r) vs T. These critical values (min. or max. C,), together with the temperature ranges in which the solid state transformations (order/disorder) occur, depend on both the heat-treatment and the boron content of the alloy. Received 22 January 198 1 2.
SPECTRAL DEPENDENCE OF PHOTORESPONSE AND ELECTRONIC STRUCTURE OF MONOCRYSTAL OF CuInTe, N.V. Joshi & Ht Aguilar, Department0 de Fiscia, Universidad de Los Andes, MCrida, venezuala.
The photoconductivity spectrum of a single crystal of the semiconducting compound CuInTe, has been experimentally resolved into various distinct peaks at 300 K in the range - from 0.5 p to 1.5 p for the first time. The observed peaks are explained on the basis of the transitions originating - from the valence sub-band structure. Impurity level is also reflected in the photoconductivity spectrum. Received 22 June 198 1
3.
ELECTRON PARAMAGNETIC RESONANCE IN DEUTERATED NICKEL FLUOSILICATE R.S. Rubins and Talatnaz Haghighatjou, Department of Physics, BoxNo. 19059, The University of Texas at Arlington, Arlington, TX 76019, U.S.A.
Electron paramagnetic resonance measurements in single crystals of NiSiF6 - 6Ds 0 were made at K, Ku and Ka bands at 4.2 K and between 77 and 300 K. The measuredg values were in the range 2.23-2.26, while the zero-field splitting parameter D varied from - (0.185 + 0.005) cm-’ at 4.2 K to - (0.53 f 0.01) cm-’ at 298 K. The parameters of the trimolecular hexagonal unit cell were determined to be approximately a = 9.28 A, C = 9.58 A from powder X-ray diffraction measurements at room temperature. Received 29 June 1981 4.
AN INTERPRETATION OF STRUCTURAL SORTING DIAGRAMS FOR AB TYPE COMPOUNDS USING MOLECULAR ORBITAL IDEAS Jeremy K. Burdett and Sarah L. Price, Department of Chemistry, The University of Chicago, Chicago, Il60637, U.S.A.
The factors governing the structure adopted by a particular AB compound are investigated by deriving two parameters reflecting aspects of the interaction between A and B, using simple molecular orbital ideas, which can be quantified bu use of atomic parameters derived from pseudopotential theory. A plot of the values of these two parameters, for a large database of compounds, produces a remarkable topological clustering of AB compounds with the same structure. This structural sorting can also be effected for nonoctet AB compounds if the number of electrons is taken into account. These parameters are related to other indices, Ro, R,, previously used by Bloch, Zunger, Phillips and coworkers to construct structural sorting diagrams. Hence we find a justification for the success of such displays, and shed light on the reasons underpinning structural