Universität zu Köln

Qureshi, N., Valldor, M., Weber, L., Senyshyn, A., Sidis, Y. and Braden, M. (2015). Magnetic spin-flop transition and interlayer spin-wave dispersion in PrCaFeO4 revealed by neutron diffraction and inelastic neutron scattering. Phys. Rev. B, 91 (22). COLLEGE PK: AMER PHYSICAL SOC. ISSN 2469-9969

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Abstract

We present a comprehensive study on PrCaFeO4 using macroscopic methods, neutron and x-ray diffraction, as well as inelastic neutron scattering. One polycrystalline and two single-crystal samples were investigated exhibiting structural phase transitions from a high-temperature tetragonal phase to an intermediate orthorhombic phase (space group Bmeb) at 510 degrees C (783 K). At approximately 240 K a second structural phase transition takes place into the space group Pccn where the tilt axis of the FeO6 octahedra changes from the [100] to the < 110 > directions. Due to strong diffuse scattering at high temperatures neutron powder diffraction can only safely state that T-N is above 330 K. PrCaFeO4 exhibits a magnetic spin-flop phase transition where the magnetic moments turn from the b axis to the c axis upon cooling. However, the transition temperatures and the width of this magnetic transition are strikingly different between the investigated samples, suggesting a strong influence from the real structure. Indeed, a significant difference in the oxygen content was deduced by single-crystal x-ray diffraction. The magnon dispersion was studied by inelastic neutron scattering revealing a nearest-neighbor interaction comparable to that in LaSrFeO4 but with smaller anisotropy gaps. A clear interlayer dispersion was observed resulting from the structural distortions and the relief of geometrical frustration due to the orthorhombic splitting.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Qureshi, N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Valldor, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Weber, L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Senyshyn, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Sidis, Y. UNSPECIFIED UNSPECIFIED UNSPECIFIED Braden, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-401312
DOI:	10.1103/PhysRevB.91.224402
Journal or Publication Title:	Phys. Rev. B
Volume:	91
Number:	22
Date:	2015
Publisher:	AMER PHYSICAL SOC
Place of Publication:	COLLEGE PK
ISSN:	2469-9969
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language REORIENTATION TRANSITION; PHASE; LA Multiple languages Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/40131