Investigation of dielectric relaxation, Jahn-Teller distortion, and magnetic ordering in Y substituted Pr1-xYxMnO3 (0.1 <= x <= 0.4)

Yadav, Ruchika and Nair, Harikrishnan S and Kumar, Amit and Adiga, Shilpa and Bhat, HL and Yusuf, SM and Elizabeth, Suja (2015) Investigation of dielectric relaxation, Jahn-Teller distortion, and magnetic ordering in Y substituted Pr1-xYxMnO3 (0.1 <= x <= 0.4). In: JOURNAL OF APPLIED PHYSICS, 117 (9).

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Abstract

We report structural, magnetic, and dielectric properties of the perovskite compound Pr1-xYxMnO3 (0.1 <= x <= 0.4) studied using dc magnetization, ac susceptibility, neutron powder diffraction, and dielectric techniques. These compounds crystallize in orthorhombic space group (Pnma) in the temperature range 5-300 K. The Mn-O-Mn bond angle decreases with the Y substitution along with an increase in the Jahn-Teller distortion. The Jahn-Teller distortion for Pr0.9Y0.1MnO3 shows an anomalous change near 50 K, below which it falls sharply. Neutron powder diffraction patterns of all reported compositions at low temperature constitute additional magnetic Bragg peaks that suggest magnetic ordering. Magnetic reflections were indexed in the nuclear lattice with the propagation vector k = (0, 0, 0). Rietveld refinement of powder patterns conform to A type antiferromagnetic ordering where moments are aligned ferromagnetically in a-c plane and coupled nearly antiferromagnetically along b-axis resulting in a net ferromagnetic component along the b-direction. The antiferromagnetic transition temperature was deduced from dc magnetization and ac susceptibility data. The transition temperature decreases by nearly 22 K (from 81 K to 59 K) as yttrium content (x) increases from 0.1 to 0.4. Measurements reveal strong frequency dispersion in dielectric constant and dielectric loss. Activation energy and relaxation time are estimated from the Arrhenius plot. It is further shown that relaxation behaviour is altered with yttrium doping concentration. (C) 2015 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	JOURNAL OF APPLIED PHYSICS
Publisher:	AMER INST PHYSICS
Additional Information:	Copy right for this article belongs to the AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Keywords:	NEUTRON POWDER DIFFRACTION; MULTIFERROIC PROPERTIES; STRUCTURE EVOLUTION; PEROVSKITE-TYPE; PRMNO3; ER
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	24 Apr 2015 05:42
Last Modified:	24 Apr 2015 05:42
URI:	http://eprints.iisc.ac.in/id/eprint/51374

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