Otto H. Zinke - University of Arkansas Physics Department

Bulletin of the American Physical Society, v 20, Issue 4, p 645-645, 1975-ture is wide, the corrected resistivity is indeed proportionalto T except for small effects. The the&expansion should axso oont ribute to the deviation fromMatthiessen'a rule. The effect will be most pronouncedfor solids of high melting temperature and should alsonpply to other transport properties, including the latticethermal conductivity.'isupported by the U.S. Axmy Research Office - Durham.EP 8 Blectronic Properties of Metals at Low but Finite'Temperatures* David Y. Kojima (introduced by Isihars) andA. Isihara, State U. of N. Y. at Buffalo.--Based on agrond ensemble method, the electronic internal energy,specific heat and susceptibility have been evaluated moateccurntely for low but finite temperatures. The densitydependence of the correlation energy has been determinedin two different ways, one iterative and the otherdirect. The ring diagram contribution has also beendetermined with and without an rs expansion. Thefailure of the well-known r, series of the corrclatlonenergy will be pointed out. The temperature and densityvariations of the specific heat, the correlation energyand the para- and din-magnetic susceptibilities and thefield dependence of the Bemi momentum will be discussed.* Work supported by N.S.F.I3P 9 Temperature Dependence of the Nuclear Relaxationof 69~e in Copper Metal) G.SCHATZ~, M.RAFAILOVLCH, andG.D.SPROUSL!. SUNY-Stony Brook.--In order to study theebfecte of radiation damage on an im lanted impurity, wehave used the reaction 65~u(7~i,3n)6 ! Ge to populate tho9/2+, 7-4 usac level in 09~e. An external field of 8 kGwas npplied and the perturbed angular distribution of the398 keV decay y-ray was rueasured at target temperaturesvarying from 320K to 720K. At the hi&heat temperatura,no relaxation of the initial anisotropy (A2*0.13(1)) vaaobserved. At a temperaturs of 320K the initial anisotropywas slightly reduced (42-O.lO(1)) and a relaxation timeof 8?3 veec was observed. A preliminary interpretation ofthe relaation times is made by considering the inceractionof the impurity atom with mobile defecta introducedinto the solid by rsdiation damage. Further experimentswith exrended ranges of temperature and magnetic fieldare in progress."Supported in part by the National Science Foundation.+Mnx Kade Fellow, Univ. of Erlangen-Niirnberg, Germany.EP 10 Anomalous Behavior of Thornson Coefficients.O.A. ZINlFE and J.B. SAWYER, Univ. Ark., R.C. NORRIS,Toxaa Tnst., and C.E.CANADa, Mason and Hanger--Thornsoncoefficients direotly msaaured in this laboratory showa strong dependence on ambient temperature. Thedependence would have escaped thermocouple detection.Direct measurements by other investigators show thesame dependence although there has apparently beenno previous effort to interpet: it. he effect ssems toba aseociatod with thermal radiation.-- --Electrical Properties of Carbonized MicrocryetallineCellulose.* R. P. LYONS, JR. and J. J. SANTIAGO,Aerospace Research Laboratories, HPAFB, Ohio 45433; andF. DIAZ, University Of Puerto Rico. Rio Piebas, PuertoRico 009Y .--High purity mlcrocryat~line cellulose wascarbonized under partial vacuum at temperatures from600~~ isochrondly for 30 minutea. Electrical contactswere placed on cerefully cut samples. Both conventiondHall effect and Van der Pauw configurations were used,depending on the sise of the sample. Besistivity andHall voltages were measured from 7T°K to 298OK. Afterthe electronic transport measurements were done the samesemplea were ground in an agate mortar, and magneticsusceptibility by the Paraday method was measured in thename temperature range. The resistivity decreased withcarbonization temperature suggesting the coalescence orcarbon atom into clusters and the disappearance of thevolatile6 such as hydrogen. The diamagnetic susceptibilityremained constant with carbonization temperature(X = -0.40 * .03 X 10-6 emu/&) and its value is closeto the carbon ion core ewceptibility, suggesting theabsence of aromatic ring formation with its largeLandau-Peierls type diamagnetism. Measurements of dielectriclosses and permittivity aa iunctions of frequencywere performed.*Submitted by J.!!. Eleeseapecine? shock loaded with a gas gun has been deslgnedfor use in wmlc f'cturs studies. Thin flyer platescarried on flat-faced ~ro.lectlles lmmct the snecisenswhich are soft recoverid and examlnei netallo&aphicallyfor microaoopic spsll fracturse. The functlon of thereoovery system Is to separate the impacting projactllaand flyer plats from the Impacted speoimen to preventmbaequent unintentional specimen damage. This sepratlonla accompUshed vla ths in-fli@t capture of thepro jectlle and flyer plate. The specimen moves unhinderedafter impact until it is soft recovered in a separatearea. The systen has been successfully testedfor projeotile velooities up to 1050 ft/secl this velocityrange has been adequate for studies of microacopicspsll fracture.EP 13 -diesof In-TI All-LOW Temperatures. G.A. SAUNDERS, D.J. GUNTONand D.Y. CHUNG*, The Univ. of Durham,Enaland.--he indium-thallium alloys in the compositionrange 16-31 at.% 91 undergo a martensitic phasetransformation from higher temperature f.c.c.form to the lower temperature f.c.t. modification-a transformation which is well suited toultrasonic studies. Here we report the ultrasonicvelocity and attenuation measurementsnear the transition for a number of alloy compositionsat low temperatures. It is shown thatthe onset of instability of the f.c.c. andf.t.c. structures is directly associated withthe approach of (Cll-c12)/2 towards zero.*Present address : Physics Department, HowardUniversity. Work partially supported by N. S.F.SUPPLEMENTARY PROGRAMBP I4 gcoustic Mode Softenins and the Meltinqin In-T1 Allovs. G.A. Saundera, D. J. Guntonand D.Y. Chung*, m e Univ. of Durhm Enaland.-- The ultrasonic velocities and attenuationin several In-Tl alloys have been measuredvery close to the melting point Tm (to within0.99Tm) . These alloys showed acoustic modesoftening and lattice instability near theirmartensitic transition temperatures Tf. Thepurpose of this experiment is to correlatethe acoustic properties near the melt to thatnear T . In all the alloys measured (includingpu$e indium), no apparent phonon softingdue to the melting was observed. The resultswill be presented.*Present addrees: Physics Department, HowardUniversity. Work partially supported by N. S.F.