Anomalous Hall effect with variable-range hopping in Mn4-xAuxN (x = 0, 0.5) epitaxial films. (February 2020)

• Record Type: Journal Article
• Authors: Li, Dan; Wang, Gaili; Li, Hongwei; Wu, Shuxiang; Li, Shuwei
• Is Part Of: Materials research bulletin. Volume 122(2020)
• Publication Date: 2020-02
• Subjects: Manganese nitride -- Transport characteristics -- Anomalous Hall effect -- Variable-range hopping; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2019.110646
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: The curves are magnetic field dependence of transverse resistivity at 5 K, 120 K, 160 K, 200 K, and 350 K. The transverse Hall resistivity shows hole-like resistivity in low temperature range and electron-like resistivity in high temperature range. The data were measured on the Hall bar with 6 electrodes in the inset. Highlights: We elucidate Mott-type variable-range hopping at low temperature (T < 87 K). We state the transition from negative Hall resistivity to positive resisitivity as temperature rises. We verify the linear relation between nett anomalous Hall effect and longitudinal resisitivity of Mn4 -x Aux N films. We verify the origin of extrinsic skew scattering of Mn4-x Aux N films. Abstract: Single-crystalline Mn4-x Aux N (x = 0, 0.5) (Mn4 N and Mn3.5 Au0.5 N) epitaxial films were grown on MgO(001) substrates by plasma assisted molecular beam epitaxy. Mott variable-range hopping in two dimensions is the dominant transport mechanism in Mn4-x Aux N films. The linear background of anomalous Hall curves at high field corresponds to the ordinary Hall coefficient. The films show apparently different anomalous Hall behaviors from Mn4 N and other anti-perovskite nitrides due to the introduction of Au atoms. Hole-like (electron-like) anomalous Hall effect is observed at low (high) temperature. The reversal of transport type appears at 155 K where distortion of curve is found because of the competition of different carriers. The slopes of Mn4 N films lie between 7 × 10 −8 and 3.9 × 10 −7, while the slopes of Mn3.5 Au0.5 N films lie between 3.7 × 10 −4 and 1.1 × 10 −3 . The nett anomalous Hall effect presents linear relation to the longitudinal resistivity, which shows that the anomalous effects are originated from the skew scattering electrons.