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Optical anisotropy of A2B4C25 crystals
ii
ABSTRACTS OF PAPERS TO APPEAR IN Monash University, Clayton, Victoria, 3168 Australia, and K.S. Murray, Chemistry Department, Monash University, Clayton, Victoria, 3168 Australia.
A detailed experimental study of the temperature dependence of the asymmetry in the Mossbauer spectra of the dimeric iron compounds (Fe salen Cl) 2 and (Fe salen)2 0 is reported. It is proposed that the integral asymmetry of the quadrupole doublet from (Fe salen Cl) 2 is due to anisotropy in the recoil-free fraction. A theoretical study of relaxation effects describes approximately the temperature dependence of the peak height asymmetry, the main defect of the theoretical treatment being probably the neglect of crystal field splittings. Observations of the spectra at 4.2°Kin applied fields of up to 90 koe verify that the ground state for both compounds has zero spin and also lead to information conceming the polarity and asymmetry of the electric field gradients.
J. PHYS. CHEM. SOLIDS
Vol.8, No.7
OPTICAL ANISOTROPY OF A2B4C~ CRYSTALS N.A. Goryunova, L.B. Zlatkin and E.K. Ivanov, Academy of Sciences of the USSR, A.F. loffe Physico-Technical Institute, Leningrad K-21, USSR
6.
The existence of synchronism directions in CdGeP2 crystals has been revealed and the short wavelength synchronism boundary for A ~‘IF5u (hu ~ 0.7eV) has been determined from measurements of the indices of refraction of of the ordinary n0 and extraordinary ~e beams. The synchronism condition for ZnSiP2, CdSiP2 and ZnGeP2 is satisfied in the crystal transmission region due to the large value of the birefringence
The value of the linear electro-optical effect in GdGeP2 has been estimated. In the crystal transmission region it was found that ‘r~= 20 x 10-8 units CGSE.
Received 15 January 1970 5.
ELECTRONIC STATES OF INTERSTITIAL IONS IN ALKALI HALIDE CRYSTALS W. Beall Fowler and Diane N. Cope, Department of Physics, Lehigh University, Bethlehem, Penna. 18015.
Semicontinuum and continuum models are used to treat the electronic states of interstitial ions and atoms in insulating crystals. The Hartree—Fock—Slater approximation is used to treat the internal structure of the ions, in cases where such structure exists. Three systems are considered, namely, Na°in Nal, the U2 center in KC1, and Cat in KC1. In the second case, our results are somewhat at variance with those of Schechter, and cast some doubt on the vacancycentered model of the lowest excited state. Received 15 December 1969
We have found experimentally the dependence of the birefringence on the cation tetrahedral radii in ZnSiP2, CdSiP2, ZnGeP2, CdGeP2 crystals Received 27 August 1969 Revised 12 December 1969
7.
THE BOLTZMANN EQUATION FOR (111) VALLEYS IN GERMANIUM S. Chou, Division of Engineering and Applied Physics, Harvard University, Cambridge, Massachusetts 02138.
A numerical solution is presented for the usual model of electron transport in (111) valleys in n-Ge, with electric in the optical (100) direction. Calculations are forfields 77°K,with and acoustic deformation potential intravalley scattering considered. The effects of acoustic energy loss are quantitatively examined. Received 23 July 1969 Revised 29 January 1970
ABSTRACTS OF PAPERS TO APPEAR IN Monash University, Clayton, Victoria, 3168 Australia, and K.S. Murray, Chemistry Department, Monash University, Clayton, Victoria, 3168 Australia.
A detailed experimental study of the temperature dependence of the asymmetry in the Mossbauer spectra of the dimeric iron compounds (Fe salen Cl) 2 and (Fe salen)2 0 is reported. It is proposed that the integral asymmetry of the quadrupole doublet from (Fe salen Cl) 2 is due to anisotropy in the recoil-free fraction. A theoretical study of relaxation effects describes approximately the temperature dependence of the peak height asymmetry, the main defect of the theoretical treatment being probably the neglect of crystal field splittings. Observations of the spectra at 4.2°Kin applied fields of up to 90 koe verify that the ground state for both compounds has zero spin and also lead to information conceming the polarity and asymmetry of the electric field gradients.
J. PHYS. CHEM. SOLIDS
Vol.8, No.7
OPTICAL ANISOTROPY OF A2B4C~ CRYSTALS N.A. Goryunova, L.B. Zlatkin and E.K. Ivanov, Academy of Sciences of the USSR, A.F. loffe Physico-Technical Institute, Leningrad K-21, USSR
6.
The existence of synchronism directions in CdGeP2 crystals has been revealed and the short wavelength synchronism boundary for A ~‘IF5u (hu ~ 0.7eV) has been determined from measurements of the indices of refraction of of the ordinary n0 and extraordinary ~e beams. The synchronism condition for ZnSiP2, CdSiP2 and ZnGeP2 is satisfied in the crystal transmission region due to the large value of the birefringence
The value of the linear electro-optical effect in GdGeP2 has been estimated. In the crystal transmission region it was found that ‘r~= 20 x 10-8 units CGSE.
Received 15 January 1970 5.
ELECTRONIC STATES OF INTERSTITIAL IONS IN ALKALI HALIDE CRYSTALS W. Beall Fowler and Diane N. Cope, Department of Physics, Lehigh University, Bethlehem, Penna. 18015.
Semicontinuum and continuum models are used to treat the electronic states of interstitial ions and atoms in insulating crystals. The Hartree—Fock—Slater approximation is used to treat the internal structure of the ions, in cases where such structure exists. Three systems are considered, namely, Na°in Nal, the U2 center in KC1, and Cat in KC1. In the second case, our results are somewhat at variance with those of Schechter, and cast some doubt on the vacancycentered model of the lowest excited state. Received 15 December 1969
We have found experimentally the dependence of the birefringence on the cation tetrahedral radii in ZnSiP2, CdSiP2, ZnGeP2, CdGeP2 crystals Received 27 August 1969 Revised 12 December 1969
7.
THE BOLTZMANN EQUATION FOR (111) VALLEYS IN GERMANIUM S. Chou, Division of Engineering and Applied Physics, Harvard University, Cambridge, Massachusetts 02138.
A numerical solution is presented for the usual model of electron transport in (111) valleys in n-Ge, with electric in the optical (100) direction. Calculations are forfields 77°K,with and acoustic deformation potential intravalley scattering considered. The effects of acoustic energy loss are quantitatively examined. Received 23 July 1969 Revised 29 January 1970