Accession Number : AD0615960

Title :   PHONON INTERACTIONS IN CRYSTALS.

Descriptive Note : Quarterly progress rept. no. 7, 15 Nov 64-14 Feb 65,

Corporate Author : IBM WATSON RESEARCH CENTER YORKTOWN HEIGHTS N Y

Personal Author(s) : Shiren,N. S. ; Pomerantz,M. ; von Gutfeld,R. J.

Report Date : 14 FEB 1965

Pagination or Media Count : 59

Abstract : A quantitative theory of adiabatic fast passage in S = 1 systems is presented. This theory supports the qualitative arguments previously given to explain the experimental MASER results. The dynamic gain mechanism is shown to be stimulated phonon - photon double quantum emission. The attenuation of 9 Gc/s phonons in phosphorous doped Ge was measured. According to the proposed theory of attenuation caused by bound electrons in degenerate states, the attenuation of the shear wave in the (100) direction should show a maximum at about 20K. The observed attenuation shows a maximum at about 15K, confirming the theory. The implications of this attenuation mechanism for the thermal conductivity of doped Ge and Si are considered. Many observations on the thermal conductivity are explained by the attenuation in degenerate electronic states. Data are presented on the values of the acoustic energy velocity for quartz, sapphire, Na C1 and KI. The experimental values are those obtained from heat pulse propagation studies and are in good agreement with theoretical energy velocity values. The theoretical energy velocity values were determined by a special geometrical construction given by Musgrave and allow the construction of energy velocity surfaces. Values of the velocity are given that agree to within 5% of the observed heat pulse velocities. The multivalued nature of the energy surface is discussed and shown to be in good agreement with the heat pulse experiments. (Author)

Descriptors :   (*PHONONS, CRYSTALS), (*CRYSTALS, PHONONS), (*MASERS, GAIN), ACOUSTIC PROPERTIES, GERMANIUM, SILICON, IMPURITIES, ENERGY, VELOCITY, ATTENUATION, PHOTONS, CRYOGENICS, THERMAL CONDUCTIVITY, CRYSTAL OSCILLATORS, FREQUENCY CONVERTERS, MICROWAVE AMPLIFIERS, ELECTRON TRANSITIONS

Distribution Statement : APPROVED FOR PUBLIC RELEASE