Anuradha, KN and Rao, SS and Bhat, SV (2009) EPR Evidence for Premonitory Charge-Ordering Fluctuations in Hydrothermally Grown Pr0.57Ca0.41Ba0.02MnO3 Nanowires. In: Applied Magnetic Resonance, 36 (2-4). pp. 347-356.
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Electron paramagnetic resonance (EPR) and magnetic properties of nanowires of Pr0.57Ca0.41Ba0.02MnO3 (PCBMO) are studied and compared with those of the bulk material. PCBMO nanowires with diameter of 80-90 nm and length of similar to 3.5 mu m were synthesized by a low reaction temperature hydrothermal method and the bulk sample was prepared following a solid-state reaction route. The samples were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The bulk PCBMO manganite exhibits charge order at 230 K along with a ferromagnetic transition at 110 K. However, superconducting quantum interference device measurements on the PCBMO nanowires show a complete `melting' of charge ordering and a ferromagnetic transition at 115 K. This result is confirmed by the EPR intensity behavior as well. However, the EPR line width, which is reflective of the spin dynamics, shows a shallow minimum for nanowires at the temperature corresponding to the charge-ordering transition, i.e., 230 K. We interpret this result as an indication of the presence of charge-ordering fluctuations in the nanowires even though the static charge order is absent, thus heralding the occurrence of charge order in the bulk sample.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Springer.|
|Department/Centre:||Division of Physical & Mathematical Sciences > Physics|
|Date Deposited:||15 Jan 2010 09:28|
|Last Modified:||19 Sep 2010 05:53|
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