Open AccessMagnetoresistance of Ge-Si Whiskers in the Vicinity to Metal– Insulator Transition
Author(s) -
Antolii Oleksandrovych Druzhynin,
Igor Ostrovsky,
Yuriy Khoverko,
N. Lyakh-Kaguy
Publication year - 2019
Publication title -
fìzika ì hìmìâ tverdogo tìla
Language(s) - English
Resource type - Journals
eISSN - 2309-8589
pISSN - 1729-4428
DOI - 10.15330/pcss.19.2.130-133
Subject(s) - magnetoresistance , whiskers , condensed matter physics , materials science , metal–insulator transition , delocalized electron , germanium , metal , electron , magnetic field , chemistry , silicon , physics , metallurgy , composite material , organic chemistry , quantum mechanics
The magnetoresistance of GeхSi1-х (x = 0.002¸ 0.11) whiskers with an acceptor concentration (Na = 3x1018¸ 2.1019 cm-3) near the metal-insulator transition (MIT) was studied at low temperatures (4.2 - 77)K in magnetic fields up to 14 T. It is shown that at 4.2 K the magnetoresistance of the Ge-Si whiskers on thedielectric side of the MIT is quadratic, while the magnetoresistance of the crystals on the metal side of the MIThas an exponential dependence on the magnetic field. In the samples in the immediate vicinity to the MIT on thedielectric side, negative magnetoresistance was detected, whereas in metal samples with a high germaniumcontent (x = 11 at.%) an anomalous positive magnetoresistance occurs. The resulting anomalous dependences arerespectively explained by the conductivity with respect to the delocalized A+ states of the upper Hubbard bandand the increase in the electron-electron interaction in Ge-Si whiskers at increasing germanium content.