Physics and Astronomy, Ames Laboratory
Journal or Book Title
Physical Review B
We present the magnetic field dependencies of transport properties for RPtBi (R=Gd, Dy, Tm, and Lu) half-Heusler compounds. Temperature- and field-dependent resistivity measurements of high-quality RPtBi single crystals reveal an unusually large, nonsaturating magnetoresistance (MR) up to 300 K under a moderate magnetic field of H=140 kOe. At 300 K, the large MR effect decreases as the rare earth is traversed from Gd to Lu and the magnetic field dependence of MR shows a deviation from the conventional H2 behavior. The Hall coefficient (RH) for R=Gd indicates a sign change around 120 K, whereas RH curves for R=Dy, Tm, and Lu remain positive for all measured temperatures. At 300 K, the Hall resistivity reveals a deviation from the linear field dependence for all compounds. Thermoelectric power measurements on this family show strong temperature and magnetic field dependencies which are consistent with resistivity measurements. A highly enhanced thermoelectric power under applied magnetic field is observed as high as ∼100 μV/K at 140 kOe. Analysis of the transport data in this series reveals that the rare-earth-based half-Heusler compounds provide opportunities to tune MR effect through lanthanide contraction and to elucidate the mechanism of nontrivial MR.
American Physical Society
Mun, Eundeok; Bud’ko, Sergey L.; and Canfield, Paul C., "Robust tunability of magnetoresistance in half-Heusler R PtBi (R = Gd, Dy, Tm, and Lu) compounds" (2016). Physics and Astronomy Publications. 548.