Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 8: Correlated Electrons: Spin Systems and Itinerant Magnets - Frustrated Magnets I

TT 8.5: Vortrag

Montag, 31. März 2014, 10:30–10:45, HSZ 304

Magnetic and dielectric Properties of the cubic pyrochlore Nd₂Hf₂O₇ — •J.-H. Chun¹, P. G. Reuvekamp¹, R. K. Kremer¹, C. T. Lin¹, R. Glaum², and A. Bronova² — ¹Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany — ²Rheinische Friedrich-Wilhelms-Universität, Institut für Anorganische Chemie, D-53121 Bonn, Germany

The magnetic properties of rare-earth (R) pyrochlores (PC) of R₂M₂O₇, where M is a 3d or 4d transition metal, have attracted broad attention because geometrical frustration gives rise to unusual magnetic ground states and excitations like spin-ice or magnetic monopoles.[1,2] In contrast the properties and especially the magnetism of the rare-earth PCs with 5d cations are considerably less well investigated. Reasons are the close proximity of the cubic PCs to the fluorite structure and that oxides of the PC family tend to exhibit disorder involving a statistical redistribution of the metal atom cations accompanied by a redistribution of the oxygen vacancy sites. We have prepared polycrystalline samples and single-crystal of Nd₂Hf₂O₇ and investigated their structural, magnetic, thermal, lattice and dielectric properties. We report low-temperature magnetic ordering determined by heat capacity and magnetic susceptibility measurements and investigations of the dielectric properties. Measurements of the thermal expansion gave no indication of a structural phase transition down to 5 K.
J. S. Gardner, M. J. P. Gingras, and J. E. Greedan, Rev. Mod. Phys. 82 (2010) 53
A. P. Ramirez, Annu. Rev. Mater. Sci. 24 (1994) 453