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Title: Size-dependent structure and magnetic properties of DyMnO{sub 3} nanoparticles

The structure and magnetic properties of orthorhombic DyMnO{sub 3} nanoparticles with different particle sizes are investigated in this paper. With decreasing particle size, all the lattice parameters a, b, and c gradually decrease, whereas the orthorhombic distortion increases. Magnetic measurements reveal that the antiferromagnetic interaction of Mn ions is weakened due to the decrease in Mn-O-Mn bond angle. Above a critical field H*, DyMnO{sub 3} undergoes a field-induced metamagnetic transition at 4 K, which is related to the spin reversal of Dy moments. The critical field H* increases monotonically with size reduction, indicating an enhancement of the antiferromagnetic interaction of Dy ions due to the decreased distance between rare earth ions. The magnetization at 4 K and 5 T, i.e., M(4 K, 5 T) shows a non-monotonic variation with particle size d, i.e., M(4 K, 5 T) initially increases with size reduction but decreases again for d < 68 nm. A modified core-shell model, in which the ferromagnetic ordering (Dy magnetic structure) and antiferromagnetic ordering (Mn magnetic structure) coexist in the core, is proposed to explain this behavior.
Authors:
; ; ; ; ;  [1]
  1. Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Publication Date:
OSTI Identifier:
22305956
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ANTIFERROMAGNETISM; BOND ANGLE; CRITICAL FIELD; DYSPROSIUM COMPOUNDS; DYSPROSIUM IONS; INTERACTIONS; LATTICE PARAMETERS; MAGNETIC PROPERTIES; MAGNETIZATION; MANGANATES; MANGANESE IONS; NANOPARTICLES; ORTHORHOMBIC LATTICES; PARTICLE SIZE; RARE EARTHS; SPIN