Bulk compound synthesis and oxygen deficiency effect on electronic and magnetic properties of the Zn-based oxyarsenide LaZnAsO1−δ

Abstract

• Polycrystalline bulk compound LaZnAsO was synthesized for the first time. • Oxygen deficiency was introduced up to 35 at.% under a high pressure of 6 GPa. • The semiconductivity was highly robust against the oxygen deficiency up to 25 at.%. LaZnAsO has been studied mainly in the thin film form that was indicated as a wide-gap insulator with the gap size of ∼2.3 eV. We herein report the synthesis of polycrystalline bulk LaZnAsO compound for the first time under a high pressure of 6 GPa. Effect of oxygen deficiency on the electric and magnetic properties of the compound was also investigated by synchrotron X-ray diffraction and measurements of electrical resistivity, magnetic susceptibility, isothermal magnetization, and specific heat. The bulk LaZnAsO crystallized into the ZrCuSiAs-type structure with the space group P 4/ nmm , isostructural with the layered LaFeAsO . It is semiconducting with a thermal activation energy of ∼0.8 eV, and the semiconductivity was highly robust against oxygen deficiency up to 25 at.%. The virtue will benefit the development of a diluted magnetic semiconductor.