Speaker
Mr
Reyner White
(UNSW Canberra)
Description
The *R*NiAl$_4$ intermetallic series (where *R* = Ln$^{3+}$) has been the subject of much investigation over a number of years. These compounds are known to possess some interesting magnetic behaviours including multiple magnetic phases and metamagnetism. TbNiAl$_4$, ErNiAl$_4$ and NdNiAl$_4$ are all known to have incommensurate magnetic structures determined from neutron diffraction[1-3], whereas the presence of an incommensurate magnetic phase in PrNiAl$_4$ is more tentative, based only on specific heat and magnetisation measurements[4]. Recent neutron powder diffraction experiments have confirmed the presence of this incommensurate magnetic phase at 7 K and 7.5 K, well within the range of 6.9-8.1 K predicted by the specific heat data. Analysis of the diffraction patterns puts the propagation vector of the magnetic phase at ***k*** = (0.071(1), 1, 0), with the magnetic moments pointing along the *a*-axis.
[1] Hutchison W D, Goossens D J, Nishimura K, Mori K, Isikawa Y and Studer A J 2006 *Journal of Magnetism and Magnetic Materials* **301** 352-8
[2] Hutchison W D, Goossens D J, Saensunon B, Stewart G A, Avdeev M and Nishimura K 2007 *31st Annual Condensed Matter and Materials Meeting, (Wagga Wagga)* Vol. 1 (Australian Institute of Physics)
[3] Mizushima T, Isikawa Y, Sakurai J, Mori K, Fukuhara T, Maezawa K, Schweizer J and Ressouche E 1994 *Physica B* **194** 225-6
[4] Nishimura K, Yasukawa T, Mori K, Isikawa Y, Hutchison W D and Chaplin D H *2003 Japanese Journal of Applied Physics* **42** 5565-70
Primary author
Mr
Reyner White
(UNSW Canberra)
Co-authors
Prof.
Katsuhiko Nishimura
(University of Toyama)
Dr
Maxim Avdeev
(Australian Nuclear Science and Technology Organisation)
Dr
Wayne Hutchison
(The University of New South Wales)
