Gangwar Sunil, Bagga Sonika, Yadav C S
School of Physical Sciences, Indian Institute of Technology Mandi, Mandi 175075 (H.P.), India.
J Phys Condens Matter. 2024 Jun 20;36(37). doi: 10.1088/1361-648X/ad540c.
We explore the magnetotransport and thermoelectric (Seebeck and Nernst coefficients) properties of MnSnC, an antiperovskite magnetic Nodal line semimetal. MnSnC shows paramagnetic (PM) to concurrent antiferromagnetic (AFM)/ferromagnetic (FM) transition at∼ 286 K. The electrical resistivity and Seebeck coefficient indicate the importance of electron-magnon scattering in the concurrent AFM/FM regime. We observed a large positive magnetoresistance (MR) of ∼8.2 at 8 T field near magnetic transition, in the otherwise negative MR behaviour for low temperatures. The electrical resistivity and MR show a weak thermal hysteresis around the boundary of transition temperature and the width of hysteresis decreases as magnetic field increases. Interestingly the Hall and Seebeck coefficients change sign from positive to negative below the transition temperature, highlighting the different scattering for holes and electrons in this multi-band system. The Seebeck and Nernst signal exhibit two sharp anomalies; one at the transition temperature and another at ∼50 K. The anomaly at magnetic transition in the Nernst signal disappear at 8 T magnetic field, owing to the reduction of magnetic fluctuation. A pseudo-gap near the Fermi level produces an upturn with a broad minimum in the Seebeck signal.
我们研究了反钙钛矿磁性节线半金属MnSnC的磁输运和热电（塞贝克系数和能斯特系数）性质。MnSnC在约286 K时显示出顺磁（PM）到同时反铁磁（AFM）/铁磁（FM）的转变。电阻率和塞贝克系数表明在同时存在的AFM/FM状态下电子-磁振子散射的重要性。我们在磁转变附近的8 T磁场中观察到约8.2的大正磁电阻（MR），而在低温下MR行为为负。电阻率和MR在转变温度边界附近显示出微弱的热滞回，并且滞回宽度随着磁场增加而减小。有趣的是，在转变温度以下，霍尔系数和塞贝克系数从正变为负，突出了这个多能带系统中空穴和电子的不同散射。塞贝克信号和能斯特信号表现出两个尖锐的异常；一个在转变温度处，另一个在约50 K处。能斯特信号在磁转变处的异常在8 T磁场下消失，这是由于磁涨落的减小。费米能级附近的一个赝能隙在塞贝克信号中产生一个向上弯曲并伴有一个宽的最小值。
