Wustite: electric, thermodynamic and optical properties of FeO

被引：37

作者：

Schrettle, F. ^{[1
]}

Kant, Ch. ^{[1
]}

Lunkenheimer, P. ^{[1
]}

Mayr, F. ^{[1
]}

Deisenhofer, J. ^{[1
]}

Loidl, A. ^{[1
]}

机构：

[1] Univ Augsburg, Ctr Elect Correlat & Magnetism, D-86135 Augsburg, Germany

来源：

EUROPEAN PHYSICAL JOURNAL B | 2012年 / 85卷 / 05期

关键词：

TRANSITION-METAL MONOXIDES; ABSORPTION-EDGE SHIFT; MAGNETIC-PROPERTIES; ANTIFERROMAGNETIC TRANSITION; PARAMAGNETIC RESONANCE; VERWEY TRANSITION; DEFECT STRUCTURE; HEAT-CAPACITIES; LOW-TEMPERATURE; DIVALENT IRON;

D O I：

10.1140/epjb/e2012-30201-5

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

We report on a systematic optical investigation of wustite. In addition, the sample under consideration, Fe0.93O, has been characterized in detail by electrical transport, dielectric, magnetic and thermodynamic measurements. From infrared reflectivity experiments, phonon properties, Drude-like conductivity contributions and electronic transitions have been systematically investigated. The phonon modes reveal a clear splitting below the antiferromagnetic ordering temperature, similar to observations in other transition-metal monoxides and in spinel compounds which have been explained in terms of a spin-driven Jahn-Teller effect. The electronic transitions can best be described assuming a crystal-field parameter Dq = 750 cm(-1) and a spin-orbit coupling constant lambda = 95 cm(-1). A well defined crystal field excitation at low temperatures reveals significant broadening on increasing temperature with an overall transfer of optical weight into dc conductivity contributions. This fact seems to indicate a melting of the on-site excitation into a Drude behavior of delocalized charge carriers. The optical band gap in wustite is close to 1.0 eV at room temperature. With decreasing temperature and passing the magnetic phase transition we have detected a strong blue shift of the correlation-induced band edge, which amounts to more than 15% and has been rarely observed in antiferromagnets.

引用

页数：12