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Title: Enhancement in magnetocaloric properties of holmium chromite by gadolinium substitution

Abstract

HoCrO{sub 3}, Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3}, and GdCrO{sub 3} bulk powder samples were prepared by citrate route. The phase purity and the structural properties of the samples were examined by x-ray diffraction and Raman spectroscopic measurements. The dc magnetization data revealed that the Cr{sup 3+} ordering temperatures (Néel temperature) for the HoCrO{sub 3}, Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3}, and GdCrO{sub 3} samples are 140 K, 148 K, and 167 K, respectively, while the ac magnetization data revealed that the rare-earth (Ho) ordering occurs at ∼8 K for HoCrO{sub 3} and Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3} samples. Temperature-induced magnetization reversal and spin reorientation were observed in GdCrO{sub 3} bulk sample, which depends on applied magnetic field and disappears at ∼1500 Oe and 500 Oe, respectively. By fitting the dc magnetic data with Curie-Weiss law, the effective magnetic moments were calculated to be 11.66 μ{sub B}, 10.23 μ{sub B}, and 9.90 μ{sub B} for the HoCrO{sub 3}, Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3}, and GdCrO{sub 3} samples, respectively. The isothermal magnetization data showed that the magnetic behavior changed from canted antiferromagnetic in low temperature region (below Néel temperature) to paramagnetic at high temperature. It was found that Gd substitution considerably improves the magnetocaloric effect of HoCrO{sub 3}. Pure GdCrO{sub 3} bulk sample showed giantmore » magnetocaloric entropy change (31.6 J/kg K at temperature ∼5 K and at ∼70 kOe), which is higher than that for polycrystalline RMnO{sub 3}, RCrO{sub 3}, and RFeO{sub 3} bulk powder samples. This renders GdCrO{sub 3} useful for potential applications in low-temperature magnetic refrigeration.« less

Authors:
 [1];  [1];  [2]
  1. Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22597778
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANTIFERROMAGNETISM; CHROMITES; CHROMIUM IONS; CITRATES; CURIE-WEISS LAW; ENTROPY; GADOLINIUM; HOLMIUM; MAGNETIC FIELDS; MAGNETIC MOMENTS; MAGNETIC PROPERTIES; MAGNETIZATION; MANGANATES; PARAMAGNETISM; POLYCRYSTALS; POWDERS; REFRIGERATION; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0400-1000 K; X-RAY DIFFRACTION

Citation Formats

Yin, S., Jain, M., E-mail: menka.jain@uconn.edu, and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269. Enhancement in magnetocaloric properties of holmium chromite by gadolinium substitution. United States: N. p., 2016. Web. doi:10.1063/1.4959253.
Yin, S., Jain, M., E-mail: menka.jain@uconn.edu, & Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269. Enhancement in magnetocaloric properties of holmium chromite by gadolinium substitution. United States. doi:10.1063/1.4959253.
Yin, S., Jain, M., E-mail: menka.jain@uconn.edu, and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269. Thu . "Enhancement in magnetocaloric properties of holmium chromite by gadolinium substitution". United States. doi:10.1063/1.4959253.
@article{osti_22597778,
title = {Enhancement in magnetocaloric properties of holmium chromite by gadolinium substitution},
author = {Yin, S. and Jain, M., E-mail: menka.jain@uconn.edu and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269},
abstractNote = {HoCrO{sub 3}, Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3}, and GdCrO{sub 3} bulk powder samples were prepared by citrate route. The phase purity and the structural properties of the samples were examined by x-ray diffraction and Raman spectroscopic measurements. The dc magnetization data revealed that the Cr{sup 3+} ordering temperatures (Néel temperature) for the HoCrO{sub 3}, Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3}, and GdCrO{sub 3} samples are 140 K, 148 K, and 167 K, respectively, while the ac magnetization data revealed that the rare-earth (Ho) ordering occurs at ∼8 K for HoCrO{sub 3} and Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3} samples. Temperature-induced magnetization reversal and spin reorientation were observed in GdCrO{sub 3} bulk sample, which depends on applied magnetic field and disappears at ∼1500 Oe and 500 Oe, respectively. By fitting the dc magnetic data with Curie-Weiss law, the effective magnetic moments were calculated to be 11.66 μ{sub B}, 10.23 μ{sub B}, and 9.90 μ{sub B} for the HoCrO{sub 3}, Ho{sub 0.67}Gd{sub 0.33}CrO{sub 3}, and GdCrO{sub 3} samples, respectively. The isothermal magnetization data showed that the magnetic behavior changed from canted antiferromagnetic in low temperature region (below Néel temperature) to paramagnetic at high temperature. It was found that Gd substitution considerably improves the magnetocaloric effect of HoCrO{sub 3}. Pure GdCrO{sub 3} bulk sample showed giant magnetocaloric entropy change (31.6 J/kg K at temperature ∼5 K and at ∼70 kOe), which is higher than that for polycrystalline RMnO{sub 3}, RCrO{sub 3}, and RFeO{sub 3} bulk powder samples. This renders GdCrO{sub 3} useful for potential applications in low-temperature magnetic refrigeration.},
doi = {10.1063/1.4959253},
journal = {Journal of Applied Physics},
number = 4,
volume = 120,
place = {United States},
year = {Thu Jul 28 00:00:00 EDT 2016},
month = {Thu Jul 28 00:00:00 EDT 2016}
}