Large 3D anisotropy of magnetoresistance in MoAlB

Abstract

Materials with large three-dimensional (3D) anisotropic magnetoresistance (MR) have very important applications in anisotropic magnetoresistance sensors and magnetometers. Herein, we have observed a large 3D anisotropy of MR in nonmagnetic MoAlB single crystal. Specially, the MR ratio (MRa: MRb: MRc) reaches up to 140.5 : 1: 22, when electric current is along a-/b-/c-axis with an applied magnetic field of 8.5 T at 5 K. To clarify the origins of 3D anisotropic MR, angular MR and direction-dependent Hall coefficient measurements as well as first-principles calculations were performed. The nearly electron-hole compensation and the mixed d-p orbital texture are the important origins of the MR effect along a-/c-axis, and the anisotropy of MR originates from the anisotropic Fermi surface and carrier scattering along a-/c-axis in MoAlB. Whereas, the open orbit is a dominant origin along b-axis of MoAlB. Furthermore, the factors affecting the magnitude of MR are given by using two-band model, and possible control strategies are proposed. This work not only proposes a new idea for exploring single-phase nonmagnetic 3D anisotropic MR material, but also provides a key material for the design and development of new 3D anisotropic magnetoresistance sensors and magnetometers in the future.