Features Peculiar to Transport Phenomena in Cobalt‐Doped HgSe Crystals

Abstract

On Hg,-,Co,Se (5 x lo-' 2 x 2 1 x lo-*) crystals the Hall coefficient, resistivity, and Shubnikovde Haas oscillations of transverse magnetoresistance are measured. Experimental findings permit the conclusion that in mercury selenide, cobalt atoms form a resonance donor level. However, by contrast with mercury selenide crystals doped with iron and chromium, the cobalt impurity does not lead to the known electron mobility "anomaly" due to the ordering of the system of charged impurities. Shubnikov-de Haas oscillations exhibit peculiarities arising from a substantial exchange interaction of conduction band electrons with 3d electrons of cobalt ions.Ha KpIICTXKXiX Hg,-,CO,Se ( 5 X lo-' 2 X 5 1 X H3MepeHbI K03@@HlWieHT XOJIJIa, YAeJIbHOe COllpOTHBJIeHHe II OClIHJIJIfllPiH ~y6HIIKOBa-Ae raa3a IlOIIepeYHOrO MaTHPiTOCOnPOTHBJIeHIIfl. 3KCIIe-PHMeHTaJIbHbIe AaHHbIe II03BOJIRWT 3aKJIWYHTb, YTO aTOMbI KO6aJIbTa 06pa3yWT B CeJIeHHAe PTYTll pe3OHaHCHbIfi AOHOPHbIfi ypOBeHb. OAHaKO, B OTJIHYHe OT KpIICTaJIJIOB CeJIeHAAa PTYTH, JIerHpOBaHHbIX PeJIe30M II XPOMOM, npIIMeCb KO6aJIbTa He npIIBOAUT K H3BeCTH06 "aHOMaJIHEI" IlOAB€CKHOCTA WIeKTPOHOB, 06yCJIOBJIeHHOfi yIIOpflAOYeHHeM CElCTeMbI 3aPRXeHHbIX IIpXMeCefi. OC~HJIJIRUAH my6HII-KOBa-Ae raa3a 06HapyXIIBaIoT OCO6eHHOCTri, CBX3aHHbIe C CyLL(eCTBeHHb1M 06MeHHbIM B3aIIMOAekT-BHeM 3JIeKTpOHOB 30HbI IIPOBOAHMOCTH C 3d 3JIeKTpOHaMH HOHOB KO6aJIbTa.

Manifestation of Donor Hybridized Electron States in Magnetism of Nickel Impurities in Mercury Selenide Crystals

“…As a result of an analysis of the experimental dependence C(N Ni ) with the use of Eq. ( 2) it was found that a variant of the single ionization (ν = 1, S io = 3/2) for the Ni 3+ (3d 7 ) ion does not agree with the experimental data, since it leads to the value n 0 ≈ 2.2•10 18 cm -3 which exceeds the known Hall concentration [8]. Second variant (ν = 2, S io = 2) for the Ni 4+ (3d 6 ) ion state corresponds to the value n 0d ≈ 2.5•10 18 cm -3 which correlates with the observed Hall concentration, however, gives the value of the S io ion core spin which is different from the approved value (5/2).…”

“…The symbols are the experimental values; the solid line is the theoretical fit to Eq. (2).At last it is the variant of three-fold ionization (ν = 3) for the Ni 2+ (3d8 ) ion state that leads to good approximation of the observed dependence C(N Ni ) and to the values of effective spin S i = (1.01 ± 0.04) and the concentration of donor electrons n 0d ≈ 0.2•10 18 cm -3 . The corresponding fitting dependence obtained by the equation (2) and the experimental values of the Curie constant for HgSe:Ni are depicted in Fig.2.In this case the charge state of the Ni 2+ ion corresponds to a situation, when the nickel atoms in the crystal lattice of HgSe are isovalent substitution impurities and, analogously to the Fe 2+ and Co 2+ ions[9], form the donor energy levels in the conduction band of the semiconductor matrix…”