• Kassem, Mohamed A.
• Nakamura, Hiroyuki
• Waki, Takeshi
• Tabata, Yoshikazu

Abstract

We report the effects of Mn substitution, corresponding to hole doping, on the electronic properties of the narrow gap semiconductor, FeSb<SUB>2</SUB>, using single crystals of Fe<SUB>1-</SUB> <SUB>x</SUB> Mn <SUB>x</SUB> Sb<SUB>2</SUB> grown by the Sb flux method. The orthorhombic Pnnm structure was confirmed by powder X-ray diffraction (XRD) for the pure and Mn-substituted samples. Their crystal structure parameters were refined using the Rietveld method. The chemical composition was investigated by wavelength-dispersive X-ray spectroscopy (WDX). The solubility limit of Mn in FeSb<SUB>2</SUB> is x <SUB>max</SUB> ̃ 0.05 and the lattice constants change monotonically with increasing the actual Mn concentration. A drastic change from semiconducting to metallic electronic transports was found at very low Mn concentration at x ̃ 0.01. Our experimental results and analysis indicate that the substitution of a small amount of Mn changes drastically the electronic state in FeSb<SUB>2</SUB> as well as the Co-substitution does: closing of the narrow gap and emergence of the density of states (DOS) at the Fermi level. <P />...

Topics

• density
• impedance spectroscopy
• single crystal
• semiconductor
• powder X-ray diffraction
• chemical composition
• X-ray spectroscopy