Epitaxial Growth and Electronic Structure of a Layered Zinc Pnictide Semiconductor, beta-BaZn2As2

Abstract

BaZn2As2 is expected for a good p-type semiconductor and has two crystalline phases of an orthorhombic alpha phase and a higher-symmetry tetragonal beta phase. Here, we report high-quality epitaxial films of the tetragonal beta-BaZn2As2 were grown on single-crystal MgO (001) substrates by a reactive solid-phase epitaxy technique. Out-of-plane and in-plane epitaxial relationships between the film and the substrate were BaZn2As2 (00l)//MgO (001) and BaZn2As2 [200]//MgO [200], respectively. The full-widths at half maximum were 0.082o for a 008 out-of-plane rocking curve and 0.342o for a 200 in-plane rocking curve. A step-and-terrace structure was observed by atomic force microscopy. The band gap of beta-BaZn2As2 was evaluated to be around 0.2 eV, which is much smaller than that of a family compound LaZnOAs (1.5 eV). Density functional theory calculation using the Heyd-Scuseria-Ernzerhof hybrid functionals supports the small band gap.

6 pages, 8 figures, Thin Solid Films, in press

References in corpus (4)

• Biaxially textured cobalt-doped BaFe2As2 films with high critical current density over 1 MA/cm2 on MgO-buffered metal-tape flexible substrates
• Nickel-based layered superconductor, LaNiOAs
• Superconductivity in Epitaxial Thin Films of Co-Doped SrFe2As2 with Bilayered FeAs Structures and their Magnetic Anisotropy
• Atomically-flat, chemically-stable, superconducting epitaxial thin film of iron-based superconductor, cobalt-doped BaFe${}_2$As${}_2$

Cited by in corpus (5)

• Narrow Bandgap in beta-BaZn2As2 and Its Chemical Origins
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• Fermi surfaces and Phase Stability of Ba(Fe${}_{1-x}$M${}_x$)${}_2$As${}_2$ (M=Co, Ni, Cu, Zn)
• Magnetic Properties and Electronic Configurations of Mn Ions in the Diluted Magnetic Semiconductor Ba${}_{1-x}$K${}_x$(Zn${}_{1-y}$Mn${}_y$)${}_2$As${}_2$ Studied by X-ray Magnetic Circular Dichroism and Resonant Inelastic X-ray Scattering