Hambourger, Paul D.

English

EngagedScholarship @ Cleveland State University

Electron-Phonon Interaction in Impure Cadmium

Cleveland-Marshall College of Law

Cleveland State UniversityEngagedScholarship@CSUPhysics Faculty Publications Physics Department1976Electron-Phonon Interaction in Impure CadmiumPaul D. HambourgerCleveland State University, p.hambourger@csuohio.eduFollow this and additional works at: https://engagedscholarship.csuohio.edu/sciphysics_facpubPart of the Physics CommonsHow does access to this work benefit you? Let us know!Publisher's StatementCopyright 1976 American Institute of Physics. This article may be downloaded for personal use only.Any other use requires prior permission of the author and the American Institute of Physics. Thefollowing article appeared in Bulletin of the American Physical Society 21 (1976): 388-388 and may befound at http://www.aps.org/meetings/baps/.Repository CitationHambourger, Paul D., "Electron-Phonon Interaction in Impure Cadmium" (1976). Physics Faculty Publications. 124.https://engagedscholarship.csuohio.edu/sciphysics_facpub/124This Article is brought to you for free and open access by the Physics Department at EngagedScholarship@CSU. It has been accepted for inclusion inPhysics Faculty Publications by an authorized administrator of EngagedScholarship@CSU. For more information, please contactlibrary.es@csuohio.edu.Original CitationHambourger, Paul D. "Electron-Phonon Interaction in Impure Cadmium." Bulletin of the American Physical Society 21 (1976): 388-388.percent error in the results of molecular field theory. To demonstrate the utility of the general formula we present results of calculations for rare earth compounds of cubic symmetry which include most of the recently studied induced moment systems with singlet or nonmag­netic doublet ground state. A comparison with the molecular field theory values will also be shown. *Supported by NSF Grant OMR 73-02318 A01. lO.H. Yang and Y.L. Wang, Phys. Rev. B~, 1057 (1975)1 !Q., 4714 (1974). FK 17 l'-lagnrtic Excitations in the Dot&ed Antiferro­masnet MnF2 • B. A. pAULSON, S. CHAND , and W. M. YEN, Unlv. of WIs. -Madison -- We have used fluorescence line narrowing techniques to study the effects of impurities on the magnetic excitations in the antiferromagnet MnFZ' In addition to the pure exciton line El , the fluores­cence spectnml of MI1Fz contains the associated magnon sideband a *, which reflects the spectrum of magnetic excitation~. TIle presence of impurities alters the magnon spectnun, but the corresponding changes in the magnon sideband are masked by a simultaneous broadening of the exciton state. Using a narrow band dye laser, we have pumped within the broadened p:rofile of ~, to observe changes in the magnon spectrum without inter­ference fram the inhomogeneities extant in the exciton transition. TIle dynamics of transfer to impurity sites may also be obtained through the study of time WEDNESDAY AFTERNOON, 31 MARCH 1976 FLEMISH SUITE AT 2:00 P.M. ltV. Coleman, presiding FL 1 The Electron-Electron Interaction in Simple Met­als. CARL KUKKONENT and JOHN WILKINS, Cornell U. --The effective many-body interaction between two electrons in a uniform electron gas is investigated and an approxi­mate form is used to calculate the electron-electron scattering contribution to the thermal resistivity - a quantity recently measured in Na. We find that: i) Our approximation to the interaction depends strongly on the vertex and dielectric functions of the uniform electron gas; ii) These functions must satisfy the compressibility sum rule, and this makes the effective electron-electron interaction stronger than the Thomas-Fermi interaction; iii) In a real metal one must also consider the contri­bution to the total dielectric function from the polari­zation of core electrons; and iv) The thermal resistivity predicted by our approximate interaction is consistent with experimental results recently obtained for Na, whereas the Thomas-Fermi result is too small by a factor of seven. The calculated thermal resistivities of K. Rb. and Cs are larger than that of Na and are much more sen­sitive to the precise values of the compressibility and core polarization. Therefore future measurements on these metals should constitute a severe test of our theo­retical treatment. tpresent address: Purdue University FL 2 Electron-Phonon Collision Frequency on the Fermi Surface of Silver and Copper.* P. B. JOHNSON and R. G. GOODRICH. Louisiana State U.--Tbe anisotropy of the electron-phonon collision fre~uency on the Fermi surface of silver and copper has been determined from RFSE measurements. The average collision fre~uency about a series of parallel field and limiting point orbits was determined from the temperature dependence of the evolution of the spectra following pulse excitation. *Research sponsored by the National Science Foundation. FK18 Comparison of the Molecular Exchange Field Splitting in the 4A2 and 4T2 states in Magnetically-Ordered CrC13*' VICTOR M. BERMUDEZt and DONALD S. McCLURE; Frick Chemi­cal ~ab., ¥rinceton Univ.--We have analyzedtheA2 ~T2 crystal field 'transition in meta­magnetic CrC13 . A long progression in the 250 cm-l E unit cell vibration is observed, and a perturBation calculation for the zero-phonon level, based on the octahedral cluster approxi­mation, yields a Jahn-Teller energy of 500±80 cm-. The exchange splitting of the zero­phonon level (which is considerably larger than the "quenchegn spin-orbit ~Plitting) indicates that the Cr+ (4T21 - Cr+3 ( A2 ) interaction is antiferromagnetic and slightly smaller in mag­nitude (HEX ~ 300Kgau~S vs. ~ 3§O~gauss) than the ferromagnetic Cr+ (4A2)-Cr+ ( A2) interac­tion. *Supported by N.S.F. and O.N.R. tpresent address: Naval Research Lab., Wash. D.C. TRANSPORT IN METALS I corresponding RFSE signal amplitudes. In all cases when inA is plotted versus T3 the expected linear relation­ship is obtained. Using the average values of the collision fre~uency for the parallel field orbits in an inversion techni~ue. a functional ~orm for the collision frequency over the Fermi surface was determined. Several different functional forms were assumed in order to determine the best fit to the experimental data. Using the best functional fit the average values o~ the collision f~e~uency about the measured limiting point orbits were calculated and compared with the measured values. *Supported by National Science Foundation, Grant No. DMR73-02427. FL 3 E1 ectron- Phonon Interacti on in Impu re Cadmium.* P. D. HAMBOURGER, Cleveland state U. --Temperature dependence of e1ectron mean free path has been measured by means of the size-dependent oscil­latory magnetoresistance effectl in the temperature range 1.3<T<3.2 K in a cadmium samp1e2 containing1 PPM silver (RRR=13,OOO) and compared with data from purer samp1es1 (RRR=30,OOO-40,OOO). For a complexorbit on t~e 2nd-zone "monster", we find R.-1 (T) =R.-1 (O)+AT. A is identical in all samples to within the experimental uncertainty of :10% despite the large variation of impurity scattering rate implied by the RRR values, thereby setting an upper limit on the coupling between the electron-phonon and electron­impurity interactions for this orbit. *Submitted by K. J. CASPER 1p. D. Hambourger, Low-T~mperature Ph}SiCS - LT 13, Vol. 4, (Plenum Press, New York, 1972 p. 278. 2Cut from a crystal grown by D. A. Lilly and kindlylent by A. N. Gerritsen. 388 

https://engagedscholarship.csuohio.edu/cgi/viewcontent.cgi?article=1123&amp;context=sciphysics_facpub

Electron-Phonon Interaction in Impure Cadmium

Abstract

Similar works

Full text

Available Versions

EngagedScholarship @ Cleveland State University

Cleveland-Marshall College of Law