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Title: Lattice collapse and quenching of magnetism in CaFe[subscript 2]As[subscript 2] under pressure: A single-crystal neutron and x-ray diffraction investigation

Abstract

Single-crystal neutron and high-energy x-ray diffraction measurements have identified the phase lines corresponding to transitions among the ambient-pressure paramagnetic tetragonal (T), the antiferromagnetic orthorhombic (O), and the nonmagnetic collapsed tetragonal (cT) phases of CaFe{sub 2}As{sub 2}. We find no evidence of additional structures for pressures of up to 2.5 GPa (at 300 K). Both the T-cT and O-cT transitions exhibit significant hysteresis effects, and we demonstrate that coexistence of the O and cT phases can occur if a nonhydrostatic component of pressure is present. Measurements of the magnetic diffraction peaks show no change in the magnetic structure or ordered moment as a function of pressure in the O phase, and we find no evidence of magnetic ordering in the cT phase. Band-structure calculations show that the transition into the cT phase results in a strong decrease in the iron 3d density of states at the Fermi energy, consistent with a loss of the magnetic moment.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1005643
Resource Type:
Journal Article
Journal Name:
Phys. Rev. B
Additional Journal Information:
Journal Volume: 79; Journal Issue: (2) ; 2009; Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
ENGLISH
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ARSENIC COMPOUNDS; CALCIUM COMPOUNDS; DENSITY; DIFFRACTION; FUNCTIONS; HYSTERESIS; IRON; IRON COMPOUNDS; MAGNETIC MOMENTS; MAGNETISM; NEUTRONS; PEAKS; PRESSURE RANGE GIGA PA; QUENCHING; TEMPERATURE RANGE 0273-0400 K; X-RAY DIFFRACTION

Citation Formats

Goldman, A I, Kreyssig, A, Prokeš, K, Pratt, D K, Argyriou, D N, Lynn, J W, Nandi, S, Kimber, S A.J., Chen, Y, Lee, Y B, Samolyuk, G, Leão, J B, Poulton, S J, Bud'ko, S L, Ni, N, Canfield, P C, Harmon, B N, McQueeney, R J, HZB), Ames), and NIST). Lattice collapse and quenching of magnetism in CaFe[subscript 2]As[subscript 2] under pressure: A single-crystal neutron and x-ray diffraction investigation. United States: N. p., 2009. Web. doi:10.1103/PhysRevB.79.024513.
Goldman, A I, Kreyssig, A, Prokeš, K, Pratt, D K, Argyriou, D N, Lynn, J W, Nandi, S, Kimber, S A.J., Chen, Y, Lee, Y B, Samolyuk, G, Leão, J B, Poulton, S J, Bud'ko, S L, Ni, N, Canfield, P C, Harmon, B N, McQueeney, R J, HZB), Ames), & NIST). Lattice collapse and quenching of magnetism in CaFe[subscript 2]As[subscript 2] under pressure: A single-crystal neutron and x-ray diffraction investigation. United States. doi:10.1103/PhysRevB.79.024513.
Goldman, A I, Kreyssig, A, Prokeš, K, Pratt, D K, Argyriou, D N, Lynn, J W, Nandi, S, Kimber, S A.J., Chen, Y, Lee, Y B, Samolyuk, G, Leão, J B, Poulton, S J, Bud'ko, S L, Ni, N, Canfield, P C, Harmon, B N, McQueeney, R J, HZB), Ames), and NIST). Fri . "Lattice collapse and quenching of magnetism in CaFe[subscript 2]As[subscript 2] under pressure: A single-crystal neutron and x-ray diffraction investigation". United States. doi:10.1103/PhysRevB.79.024513.
@article{osti_1005643,
title = {Lattice collapse and quenching of magnetism in CaFe[subscript 2]As[subscript 2] under pressure: A single-crystal neutron and x-ray diffraction investigation},
author = {Goldman, A I and Kreyssig, A and Prokeš, K and Pratt, D K and Argyriou, D N and Lynn, J W and Nandi, S and Kimber, S A.J. and Chen, Y and Lee, Y B and Samolyuk, G and Leão, J B and Poulton, S J and Bud'ko, S L and Ni, N and Canfield, P C and Harmon, B N and McQueeney, R J and HZB) and Ames) and NIST)},
abstractNote = {Single-crystal neutron and high-energy x-ray diffraction measurements have identified the phase lines corresponding to transitions among the ambient-pressure paramagnetic tetragonal (T), the antiferromagnetic orthorhombic (O), and the nonmagnetic collapsed tetragonal (cT) phases of CaFe{sub 2}As{sub 2}. We find no evidence of additional structures for pressures of up to 2.5 GPa (at 300 K). Both the T-cT and O-cT transitions exhibit significant hysteresis effects, and we demonstrate that coexistence of the O and cT phases can occur if a nonhydrostatic component of pressure is present. Measurements of the magnetic diffraction peaks show no change in the magnetic structure or ordered moment as a function of pressure in the O phase, and we find no evidence of magnetic ordering in the cT phase. Band-structure calculations show that the transition into the cT phase results in a strong decrease in the iron 3d density of states at the Fermi energy, consistent with a loss of the magnetic moment.},
doi = {10.1103/PhysRevB.79.024513},
journal = {Phys. Rev. B},
issn = {1098-0121},
number = (2) ; 2009,
volume = 79,
place = {United States},
year = {2009},
month = {6}
}