9-13 July 2012
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=11&confId=14"><font color=#ff0000>SAIP2012 PROCEEDINGS AVAILABLE</font></a>

The magnetocaloric effect in PrNiSi<sub>2</sub>

12 Jul 2012, 11:40
20m
Oral Presentation Track A - Division for Condensed Matter Physics and Materials DCMPM2

Speaker

Mr JL Snyman (University of Johannesburg)

Main supervisor (name and email)<br>and his / her institution

Prof. A.M. Strydom amstrydom@uj.ac.za University of Johannesburg

Abstract content <br> &nbsp; (Max 300 words)

The magnetocaloric effect (MCE) in lanthanide based compounds has attracted sustained interest ever since the discovery of the so called 'giant' MCE in Gd5Si2Ge2 by Pecharsky and Gshneidner [1]. Apart from its applicability in new energy efficient refrigeration technologies, the MCE is also a useful probe into the magnetic properties of a system. Recent research focuses on the interplay between the MCE and the salient features of 4f-electron magnetism [2]. In this regard PrNiSi2 offers an interesting case study. The system orders ferromagnetically below 20K [3,4] contrary to the non-magnetic ground state expected for Pr-ions in a crystalline electric field (CEF) with orthorhombic symmetry [5]. Subsequently a study of the MCE in polycrystalline PrNiSi2 is presented. An anomalous contribution to the MCE is found above the magnetic phase transition temperature. An explanation of the latter in terms of a strong uniaxial anisotropy resulting from leading terms in the CEF Hamiltonian is forwarded.

[1] V.K. Pecharsky and K.A. Gshneidner, Jr., Physical Review Letters 78 (1997) 4494
[2] N.A. de Oliveira and P.J. von Ranke, Physics Reports 489 (2010) 89
[3] P. Shobinger-Papamantellos and K.H.J. Buschow, Journal of Alloys and Compounds 185 (1992) 51
[4] A. Gil et al., Journal of Magnetism and Magnetic Materials 129 (1994) 271
[5] P. Javorsky et al., Journal of Magnetism and Magnetic Materials 186 (1999) 373

Apply to be<br> consider for a student <br> &nbsp; award (Yes / No)?

Yes

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

PhD

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Primary author

Mr JL Snyman (University of Johannesburg)

Co-author

Prof. AM Strydom (University of Johannesburg)

Presentation Materials