6533b7d7fe1ef96bd1268db4

RESEARCH PRODUCT

Verwey-type transition in EuNiP

Claudia FelserMarkus WaldeckVadim KsenofontovJürgen EnslingPhilipp GütlichHem C. KandpalAlbrecht MewisDirk Johrendt

subject

Phase transitionMaterials sciencechemistryCondensed matter physicsPhotoemission spectroscopyVan Hove singularityValencyGeneral Physics and Astronomychemistry.chemical_elementFermi energyIsostructuralEuropiumElectronic band structure

description

High temperature 151Eu Mossbauer measurements provide proof for inhomogeneous mixed-valent behaviour in EuNiP. We observed that EuNiP undergoes a Verwey-type charge delocalisation transition when heated above 470 K prior to the structural γ-β phase transition at T ≈ 510 K. This finding confirms the results of photoemission spectroscopy in the isostructural compound EuPdP and of TB-LMTO-ASA band structure calculations. We discuss the role of a van Hove singularity associated with a high density of 4f states close to the Fermi energy in inhomogeneous mixed europium valency, and the microscopic mechanism of γ-β phase transition in compounds analogous to EuNiP.

https://doi.org/10.1209/epl/i2005-10563-6