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Far infrared optical properties of free carriers in GaAs
vi
ABSTRACTS OF PAPERS TO APPEAR IN J. PHYS. CHEM. SOLIDS
overlap is omitted, and (3) halves the mobility when the two valence bands have equal effective masses with respect to the case in which inter-band scattering is omitted. Comparison with experimental mobility is good for Ge, and fair for Si due to the strong nonparabolicity of its valence bands.
mobility agree with published values and with a d.c. drift measurement.
Received 6 February 1974
6.
Received 28 February 1973 Revised 12 March 1974
4.
PRESSURE AND TEMPERATURE D E R I VATIVES OF THE ISOTROPIC POLYCRYSTALLINE SHEAR MODULUS FOR 65 ELEMENTS Michael W. Guinan and Daniel J. Steinberg, Lawrence Livermore Laboratory, Livermore, California 94550, U.S.A.
Experimental values are tabulated for the temperature derivative of the isotropic polycrystalline shear modulus for 45 elements and for the pressure derivative for 34 elements. Equations are derived to estimate these derivatives, and the estimated values generally compare well with the experimental data. These equations have been used to determine pressure and temperature derivatives of the isotropic polycrystalline shear modulus for other elements for which no experimental data are available.
Vol. 15, No. 1
ULTRASONIC STUDIES ON BISMUTHTIN ALLOYS K.K. Gopinathan and A.R.K.L. Padmini, Ultrasonics Laboratory, Physics Department, Faculty of Technology and Engineering, M.S. University of Baroda, Baroda, India.
A study of ultrasonic velocities and internal friction in Bi-Sn alloys was carried out in the concentration range of 0 - 8 . 3 atomic percent of tin using the composite oscillator technique, and a set of elastic constants was calculated from the velocity and density data. The elastic constants as well as the internal friction were found to decrease abruptly in the region of solid solution. This peculiar variation is attributed to the semiconducting properties of this alloy system in this concentration range. The temperature variation of Young's modulus was studied for some of the concentrations and Young's modulus was found to decrease linearly with increasing temperature.
Received 26 December 1973
Received 19 November 1973 7. 5.
FAR INFRARED OPTICAL PROPERTIES OF FREE CARRIERS IN GaAs R.N. Zitter and K. As'Saadi, Physics department, Southern Illinois University, Carbondale, Illinois 62901, U.S.A.
Transmission and reflection measurements over the frequency range 17-200 cm -1 were made on GaAs with electron concentrations of 1.0 and 4.9 X 1016 cm-a . The plasma frequencies of the samples fall within the measurement range. When values of the free carrier absorbtion coefficient a and the real refractive index n as derived from the data are plotted in the form (c~n)-1 vs (frequency) 2 , the plots are linear, in excellent agreement with Drude theory. Deduced values of effective mass, relaxation time and
INFLUENCE OF THE SURFACE ON THE QUANTUM P.E.M. EFFECT IN InP A. Barbaric and E. Fortin, Department of Physics, University of Ottawa, Ottawa, Canada.
The photoelectromagnetic effect of InP is studied in quantizing magnetic fields at 4.2 K in an energy range 1.4-1.5 eV for linearly polarized light. Depending on the sample surface condition two types of spectral oscillations may appear, those associated with interband transitions between Landau levels or the LO phonon type usually seen in photoconductivity. An analysis of the spectral oscillations gives: Eo = 1.423 + 0.001 eV; A o = 0.102 + 0.006 eV;hwL = 0.036 eV.
Received 17 December 1973
ABSTRACTS OF PAPERS TO APPEAR IN J. PHYS. CHEM. SOLIDS
overlap is omitted, and (3) halves the mobility when the two valence bands have equal effective masses with respect to the case in which inter-band scattering is omitted. Comparison with experimental mobility is good for Ge, and fair for Si due to the strong nonparabolicity of its valence bands.
mobility agree with published values and with a d.c. drift measurement.
Received 6 February 1974
6.
Received 28 February 1973 Revised 12 March 1974
4.
PRESSURE AND TEMPERATURE D E R I VATIVES OF THE ISOTROPIC POLYCRYSTALLINE SHEAR MODULUS FOR 65 ELEMENTS Michael W. Guinan and Daniel J. Steinberg, Lawrence Livermore Laboratory, Livermore, California 94550, U.S.A.
Experimental values are tabulated for the temperature derivative of the isotropic polycrystalline shear modulus for 45 elements and for the pressure derivative for 34 elements. Equations are derived to estimate these derivatives, and the estimated values generally compare well with the experimental data. These equations have been used to determine pressure and temperature derivatives of the isotropic polycrystalline shear modulus for other elements for which no experimental data are available.
Vol. 15, No. 1
ULTRASONIC STUDIES ON BISMUTHTIN ALLOYS K.K. Gopinathan and A.R.K.L. Padmini, Ultrasonics Laboratory, Physics Department, Faculty of Technology and Engineering, M.S. University of Baroda, Baroda, India.
A study of ultrasonic velocities and internal friction in Bi-Sn alloys was carried out in the concentration range of 0 - 8 . 3 atomic percent of tin using the composite oscillator technique, and a set of elastic constants was calculated from the velocity and density data. The elastic constants as well as the internal friction were found to decrease abruptly in the region of solid solution. This peculiar variation is attributed to the semiconducting properties of this alloy system in this concentration range. The temperature variation of Young's modulus was studied for some of the concentrations and Young's modulus was found to decrease linearly with increasing temperature.
Received 26 December 1973
Received 19 November 1973 7. 5.
FAR INFRARED OPTICAL PROPERTIES OF FREE CARRIERS IN GaAs R.N. Zitter and K. As'Saadi, Physics department, Southern Illinois University, Carbondale, Illinois 62901, U.S.A.
Transmission and reflection measurements over the frequency range 17-200 cm -1 were made on GaAs with electron concentrations of 1.0 and 4.9 X 1016 cm-a . The plasma frequencies of the samples fall within the measurement range. When values of the free carrier absorbtion coefficient a and the real refractive index n as derived from the data are plotted in the form (c~n)-1 vs (frequency) 2 , the plots are linear, in excellent agreement with Drude theory. Deduced values of effective mass, relaxation time and
INFLUENCE OF THE SURFACE ON THE QUANTUM P.E.M. EFFECT IN InP A. Barbaric and E. Fortin, Department of Physics, University of Ottawa, Ottawa, Canada.
The photoelectromagnetic effect of InP is studied in quantizing magnetic fields at 4.2 K in an energy range 1.4-1.5 eV for linearly polarized light. Depending on the sample surface condition two types of spectral oscillations may appear, those associated with interband transitions between Landau levels or the LO phonon type usually seen in photoconductivity. An analysis of the spectral oscillations gives: Eo = 1.423 + 0.001 eV; A o = 0.102 + 0.006 eV;hwL = 0.036 eV.
Received 17 December 1973