Extreme Transverse Magnetoresistance in TiZn ₁₆

ABSTRACT Extreme magnetoresistance (XMR) is a phenomenon characterized by an increase in resistance by factors of 10 ⁴ –10 ⁷ % when a magnetic field is applied. This phenomenon is found in a number of semimetals such as WTe ₂ , PtSn ₄ , Cd ₃ As ₂ , and LaSb. The origin of XMR is still hotly debated, possibly with different materials having different (or multiple) explanations. Extreme transverse magnetoresistance of up to 8000% at 14 T and 1.8 K is measured in TiZn ₁₆ , a semimetal with a multitude of bands crossing the Fermi energy, akin to PtSn ₄ . The magnetoresistance is suppressed when the magnetic field is rotated to be parallel to the applied current, similar to PtSn ₄ and PdSn ₄ . The resistance of TiZn ₁₆ follows Kohler's rule, but displays different behavior under an applied transverse field and under a longitudinal magnetic field, suggesting distinct electrical phases. Also present are Shubnikov‐de Haas and de Haas‐van Alphen oscillations with a transverse magnetic field up to 43 T, showing that despite an insulator‐like temperature‐resistance curve, charge carriers are still present. This positions TiZn ₁₆ as an interesting addition to the investigation of XMR materials as a multi‐band metal with complex Fermi surface geometries.