An electron paramagnetic resonance study of phase segregation in $Nd_{0.5}Sr_{0.5}MnO_3$

Joshi, Janhavi P and Sood, AK and Bhat, SV and Parashar, Sachin and Raju, AR and Rao, CNR (2004) An electron paramagnetic resonance study of phase segregation in $Nd_{0.5}Sr_{0.5}MnO_3$. In: Journal of Magnetism and Magnetic Materials, 279 (1). pp. 91-102.

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Abstract

We present results of an electron paramagnetic resonance (EPR) study of $Nd_{1-x}Sr_xMnO_3$ with x = 0.5 across the paramagnetic to ferromagnetic, insulator to metal transition at 260K $(T_c)$ and the antiferromagnetic, charge ordering transition $(T_N = T_{co})$ at 150 K.The results are compared with those on $Nd_{0.45}Sr_{0.55}MnO_3$ which undergoes a transition to a homogeneous A-type antiferromagnetic phase at $T_N = 230K$ and on $La_{0.77}Ca_{0.23}MnO_3$ which undergoes a transition to coexisting ferromagnetic metallic and ferromagnetic insulating phases.For x = 0.5, the EPR signals below $T_c$ consist of two Lorentzian components attributable to the coexistence of two phases.From the analysis of the temperature dependence of the resonant .elds and intensities, we conclude that in the mixed phase ferromagnetic and A-type antiferromagnetic (AFM) phases coexist.The x = 0.55 compound shows a single Lorentzian throughout the temperature range.The signal persists for a few degrees belo $T_N,$ The behaviour of the A-type AFM phase is contrasted with that of the two ferromagnetic phases present in $La_{0.77}Ca_{0.23}MnO_3$.The comparison of behaviour of Atype AFM signal observed in both $Nd_{0.5}Sr_{0.5}MnO_3$ and $Nd_{0.45}Sr_{0.55}MnO_3$ with the two FM phases of $a_{0.77}Ca_{0.23}MnO_3$, vis-$\grave{a}$-vis the shift of resonances with respect to the paramagnetic phases and the behaviour of EPR intensity as a function of temperature conclusively prove that the $Nd_{0.5}Sr_{0.5}MnO_3$ undergoes phase separation into A-type AFM and FM phases.

Item Type:	Journal Article
Publication:	Journal of Magnetism and Magnetic Materials
Publisher:	Elsevier
Additional Information:	The Copyright belongs to Elsevier.
Keywords:	Electron paramagnetic resonance;Rare earth manganites;Phase separation
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	24 Apr 2006
Last Modified:	19 Sep 2010 04:25
URI:	http://eprints.iisc.ac.in/id/eprint/6444

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