Low temperature ferromagnetic properties of the diluted magnetic semiconductor Sb2-xCrxTe3

We report on magnetic and electrical transport properties of Sb2-xCrxTe3 single crystals with 0 <= x <= 0.095 over temperatures from 2 K to 300 K. A ferromagnetic state develops in these crystals at low temperatures with Curie temperatures that are proportional to x (for x > 0.014), attaining a maximum value of 20 K for x = 0.095. Hysteresis below TC for applied field parallel to the c-axis is observed in both magnetization and Hall effect measurements. Magnetic as well as transport data indicate that Cr takes the 3+ (3d3) valence state, substituting for antimony in the host lattice structure, and does not significantly affect the background hole concentration. Analysis of the anomalous Hall effect reveals that skew scattering is responsible for its presence. These results broaden the scope of ferromagnetism in the V2-VI3 diluted magnetic semiconductors (DMS) and in ferromagnetic DMS structures generallyComment: 24 pages, 5 figures, submitted to PR

Magnetic and transport properties of the V2–VI3V2–VI3 diluted magnetic semiconductor Sb2−xMnxTe3Sb2−xMnxTe3

We have measured electrical and magnetic properties of single crystals of Sb2−xMnxTe3Sb2−xMnxTe3 with x=0–0.045x=0–0.045 at temperatures of 2 K to 300 K. Hall effect measurements indicate that each manganese atom donates approximately one hole to the valence band. The magnetic susceptibility is paramagnetic down to 2 K, and both Curie–Weiss and Brillouin analyses show that manganese substitutes for Sb and takes the Mn2+Mn2+ state with S=5/2.S=5/2. Contrary to the case of III–V host matrices, manganese does not stimulate ferromagnetic order in the family of bulk layered V2–VI3V2–VI3 diluted magnetic semiconductors, at least in the range of magnetic impurity and carrier concentrations studied here. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70033/2/JAPIAU-94-12-7631-1.pd

nn-type to pp-type crossover in quaternary BixSbyPbzSe3BixSbyPbzSe3 single crystals

We report on the preparation and some physical properties of a quaternary system based on Bi2Se3Bi2Se3 codoped with Sb and Pb. Single-crystal samples were prepared using the Bridgman technique and were characterized by measurements of the lattice parameters, electrical resistivity, Hall coefficient, Seebeck coefficient, and thermal conductivity. Atomic emission spectroscopy was used to find the concentration profiles of Sb and Pb along the single-crystalline ingots. Progressive codoping of the Bi2Se3Bi2Se3 crystal lattice with Sb and Pb leads to a crossover of the initially nn-type conduction to that of the pp type. It is assumed that both Sb and Pb enter the Bi sublattice. Physical properties as well as the change in the dominant carrier type are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87555/2/103720_1.pd