Weak-field Magnetoresistance and the Valence-Band Structure of SnTet

Some time ago, we found that the weak-field magnetoresistance in /)-type SnTe exhibits a peculiar symmetry which, moreover, lb ^ong function of both carrier density and temperature. ■ The main purpose of this paper is to describe a conceptually simple model which can account for this unusual behavior in a straightforward way. Section II is concerned with experimental details, and Sec. Ill presents and discusses the magnetoresistance (MR) measurements. Because of their unusual nature, the question oi the reliability of the data is examined in some detail. The apparently contradictory nature of the weak-field MR and strong-field data is next considered, and two earlier attempts to explain the weak-field MR arc briefly reexamlned. A new model Is then proposed, and Its relevance to the weak-field MR ^r.ta. as well as to the clastir constants and the iastoreslstance of SnTe. is examined. Some observations about the quamative behavior of the thermoelectric power, flail eoetficlent, and Hall mobility are also iiulu.lcd. The final section ot the discussion crnsidcrs s.mie <>l the unifying features of the band structure« of the Pb, , SivTe and Dl,.,Sbt systems. The column-V semimelals (As. Sb. Bl» and the IV-VI semiconducting compounds (IV Ge, Sn. '>r PbVI -S. ric. or Tel form a close-knll family ••! m lerials with a number o( «Imllar phyi^al and electronic properties. These BlmUartm <• «re discussed in -any ol the paper» in-ro Ihw conferences which dealt wltn «he matcrtal«. Doth PbTc and SnTe coa««!!»«*" » "*' • • ture. and form alnnle-phaa« allo>» a« all com|».*itlona. Exceaa It and Te make PbTe * and ^ typr reapccttvely. bul in Ihe CM« «»I SnTe. Mm »"H*»» (leid llea enlir«ly on H» T»-rtdi ««le o< •i,*<**nm etry. Many dlHerent propertl« «^ »•<»« «»«• ptiunda hare bee« ahuHed eatenrteely Her» *e will only mention four relevant types of measurements-electrical, galvanomagnetlc. thermoelectric transport, and optlcal-on'" PbTe and SnTei 1.2,13.25,32-57