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Structural characterization and magnetic properties of single‐crystalline (La 0.6 Pr 0.4 ) 0.67 Ca 0.33 MnO 3 nanowires
Author(s) -
Xia Weiren,
Leng Kai,
Tang Qingkai,
Yang Li,
Xie Yuting,
Wu Zhiwei,
Yi Kang,
Zhu Xinhua
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17773
Subject(s) - nanowire , curie temperature , magnetization , orthorhombic crystal system , materials science , ferromagnetism , condensed matter physics , lattice constant , magnetic moment , atmospheric temperature range , crystallography , magnetic hysteresis , hysteresis , crystal structure , analytical chemistry (journal) , nanotechnology , magnetic field , chemistry , diffraction , physics , chromatography , quantum mechanics , optics , meteorology
Herein, structural and magnetic properties of single‐crystalline (La 0.6 Pr 0.4 ) 0.67 Ca 0.33 MnO 3 nanowires synthesized via a hydrothermal process are reported. The nanowires are crystallized in an orthorhombic structure ( Pnma space group). Their lattice parameters follow the relationship a ≈ c ≈ b /√2 . These nanowires exhibited a clean and smooth surface with diameters of 60‐120 nm and an average length of approximately 2.0 μm. High‐resolution transmission electron microscopy images confirmed the single‐crystalline nature of the nanowires growing along the [100] direction. The nanowires demonstrated magnetic hysteresis loops at low temperatures and a weak exchange bias (EB) effect. Paramagnetic (PM)–ferromagnetic (FM) phase transition occurred at a Curie temperature ( T C ) of 224 K, and strong irreversibility between zero‐field‐cooled (ZFC) and field‐cooled (FC) magnetization ( M ZFC and M FC , respectively) curves was observed at 273 K. The M ZFC curve exhibited a significantly broad peak with a maximum at a freezing temperature ( T f ) of 134 K. Relative difference between M FC and M ZFC in the nanowires [( M FC − M ZFC )/ M FC ] rapidly increased below T f and reached approximately 50% below 35 K. The effective magnetic moment deduced from the Curie constant is larger than the theoretical value, indicating short‐range FM interactions in the nanowires. A positive PM T C ( θ p ) implies dominant FM interactions in the nanowires, and θ p > T C observed herein indicates the existence of short‐range ordered states above T C .