Large linear non-saturating magnetoresistance and high mobility in ferromagnetic MnBi

Abstract

A large non-saturating magnetoresistance has been observed in several nonmagnetic topological Weyl semi-metals with high mobility of charge carriers at the Fermi energy. However, ferromagnetic systems rarely display a large magnetoresistance because of localized electrons in heavy d bands with a low Fermi velocity. Here, we report a large linear non-saturating magnetoresistance and high mobility in ferromagnetic MnBi. MnBi, unlike conventional ferromagnets, exhibits a large linear non-saturating magnetoresistance of 5000% under a pulsed field of 70 T. The electrons and holes’ mobilities are both 5000 cm2V−1s−1 at 2 K, which are one of the highest for ferromagnetic materials. These phenomena are due to the spin-polarised Bi 6p band’s sharp dispersion with a small effective mass. Our study provides an approach to achieve high mobility in ferromagnetic systems with a high Curie temperature, which is advantageous for topological spintronics.

Effect of Magnetic Impurities on Superconductivity in LaH10

“…Low‐field measurements in (La,Nd)H 10 doped by 9 at% of Nd (Figure 3a) indicate a peculiar dependence of the magnetoresistance (MR, Figure 3c): curved, approximately quadratic ρ = ( R − R 0 )/ R 0 = µ 2 H 2 at low fields , where µ is the electron mobility ( Table 1 ), and linear ρ = αH at fields above 7–9 T. In the experiment with a pulsed magnetic field, a trend of a linear resistance increase with the field is seen despite the noise (Figure 3f). The linear behavior of the magnetoresistance is typical for polycrystalline metals with an open Fermi surface (e.g., spherical with “necks”), for example, Li, Cu, Ag, Au, SrZnSb 2 [ 60 ] , MnBi, [ 61 ] and others. [ 62 ] This was explained by Lifshitz and Peschanskii in 1959 by considering the shape of the Fermi surface and the anisotropy of the MR.…”

Electrochemistry in Magnetic Fields

“…Other magnetic phenomena may also influence the electrochemical reactions and deserve further attention, such as the room‐temperature magnetoresistance effect, [75] the Hall effect, [76] and magnetostriction [77] . As the term indicates, the magnetoresistance field means the electrical resistance can be changed when the magnetic field is applied [64] .…”

Effect of paramagnetic impurities on superconductivity in polyhydrides: s-wave order parameter in Nd-doped LaH10

“…In the experiment with a pulsed magnetic field, a trend of a linear resistance increase with the field is seen despite the noise (Figure 3f). The linear behavior of the magnetoresistance is typical for polycrystalline metals with an open Fermi surface (e.g., spherical with "necks"), for example, Li, Cu, Ag, Au, SrZnSb2 55 , MnBi 56 and others. 57 This was explained by Lifshitz and Peschanskii in 1959 by considering the shape of the Fermi surface and the anisotropy of the MR.…”