Lattice and magnetic instabilities in CaFe2As2: A single-crystal neutron diffraction study

TitleLattice and magnetic instabilities in CaFe2As2: A single-crystal neutron diffraction study
Publication TypeJournal Article
Year of Publication2008
AuthorsGoldman AI, Argyriou DN, Ouladdiaf B, Chatterji T, Kreyssig A, Nandi S, Ni N, Bud'ko SL, Canfield PC, McQueeney RJ
Journal TitlePhysical Review B
Volume78
Pages100506
Date PublishedSep
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000259690400016
Keywords43 k, lao1-xfxfeas, superconductivity
Abstract

Neutron diffraction measurements of a high-quality single crystal of CaFe2As2 are reported. A sharp transition was observed between the high-temperature tetragonal and low-temperature orthorhombic structures at T-S=172.5 K (on cooling) and 173.5 K (on warming). Concomitant with the structural transition, the Fe moments order in a commensurate antiferromagnetic structure with a saturated moment of 0.80(5)mu(B)/Fe directed along the orthorhombic a axis. The hysteresis of both the structural and magnetic transitions is 1 K between cooling and warming, consistent with previous thermodynamic, transport, and single-crystal x-ray studies and provides clear evidence of the coupling between the structural and magnetic transitions in this material.

DOI10.1103/PhysRevB.78.100506
Alternate JournalPhys. Rev. B