arXiv subjects

S. Kar-Narayan

Publications and source records attributed to S. Kar-Narayan.

2 recordsLinked to original sources

arXiv2010

Absence of charge-density-wave sliding in epitaxial charge-ordered Pr0.48Ca0.52MnO3 films

For an epitaxial Pr0.48Ca0.52MnO3 film on NdGaO3, we use transmission electron microscopy to observe a "charge-ordered" superlattice along the in-plane direction a. The same film shows no electrical signatures of charge order. The in-plane electrical anisotropy (rho)a/(rho)c = 28 is constant, and there is no evidence of sliding charge density waves up to the large field of ~10^3 V/cm.

cond-mat.str-el↗

arXiv2009

Direct and indirect electrocaloric measurements using multilayer capacitors

We report the discovery of serendipitous electrocaloric effects in commercial multilayer capacitors based on ferroelectric BaTiO3. Direct thermometry records ~0.5 K changes due to 300 kV cm-1, over a wide range of temperatures near and above room temperature. Similar results are obtained indirectly, via thermodynamic analysis of ferroelectric hysteresis loops. We compare and contrast these two results. Optimised electrocaloric multilayer capacitors could find applications in future cooling technologies.

cond-mat.mtrl-sci↗