Effect of order parameter on the magnetotransport properties of half-Heusler LaPtBi

We studied the correlations among the structural properties, valence band spectra, and electrical properties of (111)-oriented half-Heusler LaPtBi thin films. An increase in the C1 order parameter led to a marked change in the valence band spectra just below the Fermi energy, indicating the dominant role of ordering at the Pt sites in the electronic structure of LaPtBi. Magnetotransport measurements at 4.2K showed that the linearity rather than the classic quadratic component of magnetoresistance becomes more evident with increasing C1 order parameter. The unique electronic structure of LaPtBi showed various quantum phenomena related to zero-gap semiconductivity. (C) 2015 The Japan Society of Applied Physics