Description: Frustrated spin correlations in diluted spin ice Ho_2-x La_x Ti_2 O

This title appears in the Scientific Report : 2008

Frustrated spin correlations in diluted spin ice Ho_2-x La_x Ti_2 O_7

We have studied the evolution of the structural properties as well as the static and dynamic spin correlations of spin ice Ho2Ti2O7, where Ho was partially replaced by non-magnetic La. The crystal structure of diluted samples Ho2-xLaxTi2O7 was characterized by x-ray and neutron diffraction and by Ho...

Personal Name(s):	Ehlers, G.
	Mamontov, E. / Zamponi, M. / Faraone, A. / Qiu, Y. / Cornelius, A. L. / Booth, C.H. / Kam, K.C. / LeToquin, R. / Cheetham, A. K. / Gardner, J. S.
Contributing Institute:	JCNS; JCNS Streumethoden; IFF-4 Neutronenstreuung; IFF-5
Published in:	Journal of physics / Condensed matter, 20 (2008) S. 235206
Imprint:	Bristol IOP Publ. 2008
Physical Description:	235206
DOI:	10.1088/0953-898/20/23/235206
Document Type:	Journal Article
Research Program:	Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) Kondensierte Materie
Series Title:	Journal of Physics: Condensed Matter 20
Subject (ZB):	J
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1088/0953-898/20/23/235206 in citations.

We have studied the evolution of the structural properties as well as the static and dynamic spin correlations of spin ice Ho2Ti2O7, where Ho was partially replaced by non-magnetic La. The crystal structure of diluted samples Ho2-xLaxTi2O7 was characterized by x-ray and neutron diffraction and by Ho L-III-edge and Ti K-edge extended x-ray absorption fine structure (EXAFS) measurements. It is found that the pyrochlore structure remains intact until about x = 0.3, but a systematic increase in local disorder with increasing La concentration is observed in the EXAFS data, especially from the Ti K edge.Quasi-elastic neutron scattering and ac susceptibility measurements show that, in x <= 0.4 samples at temperatures above macroscopic freezing, the spin -spin correlations are short ranged and dynamic in nature. The main difference with pure spin ice in the dynamics is the appearance of a second, faster, relaxation process.