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Magnetic Freeze‐Out and Magnetic‐Field‐Induced Semiconductor–Semimetal Transition in Bi 1− x Sb x Alloys under High Hydrostatic Pressure
Author(s) -
Kraak W.,
Troppenz U.,
Herrmann R.,
Chudinov S. M.,
Kulbachinskii V. A.
Publication year - 1988
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221480131
Subject(s) - condensed matter physics , magnetoresistance , hydrostatic pressure , magnetic field , semimetal , materials science , impurity , electrical resistivity and conductivity , single crystal , chemistry , physics , band gap , crystallography , organic chemistry , quantum mechanics , thermodynamics
The galvanomagnetic properties of extremely pure single‐crystal Bi 1− x Sb x alloys ( x ≈ 0.07 to 0.08) are investigated under hydrostatic pressure with static magnetic fields in the range 0 to 6 T. A striking anomalous behaviour of the longitudinal magnetoresistance ( B ∥ C 3 ) is observed in pure crystals ( n < 10 14 cm −3 ) which occurs as the magnetic field is increased above a certain critical value. At low magnetic fields and at high magnetic fields the electrical resistivity increases with increasing temperature in a metallic manner in contrast to the thermally activated behaviour observed at intermediate fields. A strong enhancement of the observed anomalies under hydrostatic pressure is found. An analysis of the results shows that the anomalous properties are associated with charge carrier freeze‐out effect in the intermediate field regime and a magnetic‐field‐induced semiconductor–semimetal transition in high magnetic fields. A simple schematic diagram of the band‐edge and impurity–level configuration of Bi 1− x Sb x alloys is proposed to describe the found experimental data.