Magnetism of PrFeAsO parent compound for iron-based superconductors: Mossbauer spectroscopy study

JOURNAL OF ALLOYS AND COMPOUNDS

卷:717

Article

Komedera, K.¹  Pierzga, A.¹  Blachowski, A.¹  Ruebenbauer, K.¹  Budziak, A.²  Katrych, S.³  Karpinski, J.³ 

[1] Pedag Univ, Inst Phys, Mossbauer Spect Div, Ul Podchorazych 2, PL-30084 Krakow, Poland

[2] Polish Acad Sci, Inst Nucl Phys, Ul Radzikowskiego 152, PL-31342 Krakow, Poland

[3] Ecole Polytech Fed Lausanne, Inst Condensed Matter Phys, CH-1015 Lausanne, Switzerland

关键词: Spin density wave;    Pr magnetic order;    Mossbauer spectroscopy;    Iron-based superconductors;   

DOI  :  10.1016/j.jallcom.2017.05.049

来源: Elsevier

【 摘 要 】

Mossbauer spectroscopy measurements were performed for the temperature range between 4.2 K and 300 K in a transmission geometry applying 14.41-keV resonant line in Fe-57 for PrFeAsO the latter being a parent compound of the iron-based superconductors belonging to the '1111' family. It was found that an itinerant 3d magnetic order develops at about 165 K and it is accompanied by an orthorhombic distortion of the chemical unit cell. A complete longitudinal 3d incommensurate spin density wave (SDW) order develops at about 140 K. Transferred hyperfine magnetic field generated by the praseodymium magnetic order on iron nuclei is seen at 12.8 K and below, i.e., below magnetic order of praseodymium magnetic moments. It is oriented perpendicular to the field of SDW on iron nuclei. The shape of SDW is almost rectangular at low temperatures and it transforms into roughly triangular form around nematic transition at about 140 K. Praseodymium magnetic order leads to the substantial enhancement of SDW due to the large orbital contribution to the magnetic moment of praseodymium. A transferred field indicates presence of strong magnetic susceptibility anisotropy in the [b-c] plane while following rotation of praseodymium magnetic moments in this plane with lowering temperature. It was found that nematic phase region is a region of incoherent spin density wavelets typical for a critical region. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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