An investigation of the magnetocaloric effect (MCE) of single-crystalline Nd1-xSrxMnO3 (x=0.3, 0.5) is presented. A large change in magnetic entropy (ΔS) is observed in anti-ferromagnet (AFM) charge-ordering compound Nd0.5Sr0.5MnO3 in a relatively low field of 1.4 T around the Néel temperature of 150 K. On the other hand, Nd0.7Sr0.3MnO3, which is a ferromagnetic (FM) metal, shows an entropy change of 3.82 J/kg K and a broad temperature dependence of adiabatic temperature change (ΔTad) over 20 K in the same low-field range around the Curie temperature (TC=203 K). Mechanism involved in the large MCE in these compounds is discussed. © 2006 Elsevier B.V. All rights reserved.

Kanikrishnan Sethupathi

Department Of Physics

M. Pattabiraman

G. Rangarajan

Antiferromagnetism

Magnetic fields

Magnetization

Neodymium alloys

Charge ordering

CMR MANGANITE

Magnetic refrigeration

Single crystals

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IIT Madras

Journal of Magnetism and Magnetic Materials

We report here the results of an electron magnetic resonance study of a single crystal of the CMR manganite, Nd0.5Sr0.5MnO3. The temperature dependence of the paramagnetic g-value, the linewidth, and the intensity point to the existence of orbitally ordered short-ranged spin correlations. The magnetocrystalline anisotropy of the sample is found to split the spectra below TC. The temperature dependence of the spectra and the angular variation of the resonance fields suggests the presence of two distinct anisotropy fields below 220 K. This is attributed to the coexistence of an A-type antiferromagnetic phase with the ferromagnetic phase down to the temperature at which a transition takes place to a charge ordered CE-type antiferromagnetic state (TCO = TN = 148K). © 2004 American Physical Society.

Physical Review B - Condensed Matter and Materials Physics

Electron magnetic resonance study in a single crystal of the colossal magnetoresistance manganite Nd0.5Sr0.5MnO3

(formula presented) nuclear magnetic resonance (NMR) in (formula presented) (formula presented) manganites provides local evidence of the magnetic inhomogeneities arising from the electronic structure changes below (formula presented) The temperature dependences of magnetization, resistivity, and NMR spectra were compared in samples in the ferromagnetic insulating, ferromagnetic metallic, and charge-ordered phases. Spin-spin relaxation enhancement around 15 K is attributed to a critical slowing down of the Nd sublattice. © 2002 The American Physical Society.

(formula presented) NMR investigation of (formula presented) (formula presented)

Journal of Applied Physics

Comparison of magnetocaloric properties from magnetic and thermal measurements

Magnetocaloric effect in single-crystalline Nd1-xSrxMnO3 (x=0.3, 0.5)

Journal	Journal of Magnetism and Magnetic Materials
ISSN	03048853
Open Access	No