Magnetotransport properties of Cr1−δTe thin films with strong perpendicular magnetic anisotropy

Abstract

P-type ferromagnetic Cr1-δTe thin films with the Curie temperature of 170K were epitaxially grown on GaAs substrate. Low-temperature magnetotransport study reveals that the film has a strong perpendicular magnetic anisotropy (PMA) and an anisotropic magnetoresistance (AMR) ratio up to 8.1%. Furthermore, reduced anomalous Hall effect is observed at low temperatures in Cr1-δTe, suggesting the possible crossover of the contribution to AHE from the intrinsic mechanism to extrinsic skew scattering. Distinctive from conventional transition metal ferromagnets, the AMR ratio is also greatly suppressed at low temperatures. Our work demonstrates that epitaxial Cr1-δTe films are interesting platforms for studying the physics underlying the strong PMA and large AMR.

Topological Hall Effect in Traditional Ferromagnet Embedded with Black-Phosphorus-Like Bismuth Nanosheets

“…The anomalous Hall resistivity depends on the magnetization M and is generally written as ρ AHE = R a M . There are usually three independent origins of the AHE, including the skew-scattering, sidejump and the Berry curvature in momentum space [2], which may have opposite contributions, thus possibly cancel with one another leading to a vanishing anomalous Hall coefficient R a [28]. Indeed, we find the sign of R a is reversed at T ∼ 42 K with decreasing temperature, and no anomalous Hall resistivity is detected right at this temperature.…”

“…Depending on the stoichiometric ratio, Cr 1−x Te has a rich structural phase diagram with Curie temperatures ranging from 170 K to 340 K [26]. Very recently, the Cr 2 Te 3 thin film with a high-quality single crystalline structure has been synthesized using the molecular beam epitaxy (MBE) technique, which shows a strong perpendicular magnetic anisotropy and a large magnetic moment per Cr atom about 2.8 µ B [27,28]. If strong spinorbit coupling elements can be doped in an appropriate way, Cr 2 Te 3 would exhibit significant THE with the onset temperature close to the Curie temperature.…”

Molecular Beam Epitaxy Grown Cr2Te3 Thin Films with Tunable Curie Temperatures for Spintronic Devices

“…To our best knowledge, the conduction type of all Cr 2 Te 3 bulk or thin film materials reported previously is p-type [1]. Cr 2 Te 3 samples grown on ZnSe in our group also show ptype feature [15]. To investigate the effect of Al contamination, A six-terminal Hall bar device was fabricated on a small piece of sample #2, as shown in Figure 6(a) for performing magneto-transport measurements.…”

“…Transport properties are measured using an Oxford Physical Property Measurement System (PPMS). and [11][12][13][14][15][16][17][18][19][20] electron beam incidence, respectively, after a pre-heat treatment was conducted. Kikuchi lines can be clearly seen in these patterns, indicating a clean and smooth surface morphology of the substrate was achieved.…”

“…Figure 1(a) & (b) are the RHEED patterns of a cleaned Al 2 O 3 (0001) surface along the and[11][12][13][14][15][16][17][18][19][20] …”