EPR studies on single crystals of $Pr_{1-x}Pb_xMnO_3$

Padmanabhan, B and Sharma, Ajay and Rao, SS and Elizabeth, Suja and Bhat, HL and Bhat, SV (2007) EPR studies on single crystals of $Pr_{1-x}Pb_xMnO_3$. In: Physica B: Condensed Matter, 398 (1). pp. 107-111.

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Abstract

Electron paramagnetic resonance (EPR) studies are carried out on single crystals of $Pr_{1-x}Pb_xMnO_3$, for x=0.23 and 0.30. The crystal with x=0.23 undergoes a transition from paramagnetic insulator to ferromagnetic insulator with Curie temperature View the MathML source. The crystal with x=0.30 undergoes a transition from paramagnetic insulator to ferromagnetic metal with Tc\sim200K. The EPR analysis is carried out in the paramagnetic region for both the crystals. The EPR signals are fitted to the Dysonian equation. Linewidth, intensity and asymmetry parameters are plotted as a function of temperature down to Tc. The intensity shows a simple Curie-Weiss behaviour. The spin relaxation takes place through a bottleneck mechanism according to which linewidth depends only on strong exchange interaction between $Mn^{3+}$ and $Mn^{4+}$ ions. Around 240 K a secondary low field EPR signal is observed for both compositions which persists till around 200 K indicating a possible phase separation.

Item Type:	Journal Article
Publication:	Physica B: Condensed Matter
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Manganites;EPR;Curie–Weiss law;Phase separation.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	17 Dec 2008 14:33
Last Modified:	19 Sep 2010 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/16710

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