Wang Kefeng, Graf D, Li Lijun, Wang Limin, Petrovic C
Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 USA.
National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306-4005, USA.
Sci Rep. 2014 Dec 5;4:7328. doi: 10.1038/srep07328.
The magnetic field response of the transport properties of novel materials and then the large magnetoresistance effects are of broad importance in both science and application. We report large transverse magnetoreistance (the magnetoresistant ratio ~ 1.3 × 10(5)% in 2 K and 9 T field, and 4.3 × 10(6)% in 0.4 K and 32 T field, without saturation) and field-induced metal-semiconductor-like transition, in NbSb2 single crystal. Magnetoresistance is significantly suppressed but the metal-semiconductor-like transition persists when the current is along the ac-plane. The sign reversal of the Hall resistivity and Seebeck coefficient in the field, plus the electronic structure reveal the coexistence of a small number of holes with very high mobility and a large number of electrons with low mobility. The large MR is attributed to the change of the Fermi surface induced by the magnetic field which is related to the Dirac-like point, in addition to orbital MR expected for high mobility metals.
新型材料输运性质的磁场响应以及由此产生的大磁阻效应在科学和应用方面都具有广泛的重要性。我们报道了在NbSb₂单晶中发现的大横向磁阻（在2 K和9 T磁场下磁阻率约为1.3×10⁵%，在0.4 K和32 T磁场下为4.3×10⁶%，且无饱和现象）以及场致金属-半导体类转变。当电流沿ac平面时，磁阻显著受到抑制，但金属-半导体类转变依然存在。磁场中霍尔电阻率和塞贝克系数的符号反转，以及电子结构表明存在少量高迁移率空穴和大量低迁移率电子的共存。除了高迁移率金属预期的轨道磁阻外，大磁阻归因于与类狄拉克点相关的磁场诱导的费米面变化。
