Large magnetoresistance and quantum oscillations of a ternary boride MoAlB single crystal

We report transport properties in a ternary compound MoAlB single crystal. It shows a metallic behavior with a residual resistivity ratio of $\ensuremath{\rho}$(300 K)/$\ensuremath{\rho}$(2 K)=40. After applied magnetic fields, the resistivity shows a quick upturn and saturates to a plateau as the temperature decreasing. At 2 K, the magnetoresistance (MR) increases quadratically with the magnetic field and reaches up to $1650%$ ($B=14$ T) without saturation. The two-band fitting of the Hall conductivity suggests that the unsaturated large quadratic MR in MoAlB was originated from the carriers' compensation with high mobility (${\ensuremath{\mu}}_h=7104\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}²\phantom{\rule{0.16em}{0ex}}{\mathrm{V}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$ and ${\ensuremath{\mu}}_e=1432\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}²\phantom{\rule{0.16em}{0ex}}{\mathrm{V}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$). The angle dependence of the ${\ensuremath{\rho}}_xx$ shows significant anisotropy. Furthermore, pronounced Shubnikov-de Haas (SdH) oscillations are observed in both magnetoresistivity and Hall resistivity. We analyzed these quantum oscillations carefully and revealed several small Fermi surfaces with the light cyclotron masses in MoAlB. The angle dependence of SdH oscillations reveals quasi-two-dimensional Fermi surface structure in MoAlB.