Muon spin relaxation studies of the frustrated quasi-two-dimensional square-lattice spin system Cu (Cl,Br) la (Nb,Ta) 2 O7: Evolution from spin-gap to antiferromagnetic state

Y. J. Uemura, A. A. Aczel, Y. Ajiro, J. P. Carlo, T. Goko, D. A. Goldfeld, A. Kitada, G. M. Luke, G. J. MacDougall, I. G. Mihailescu, J. A. Rodriguez, P. L. Russo, Y. Tsujimoto, C. R. Wiebe, T. J. Williams, T. Yamamoto, K. Yoshimura, H. Kageyama

Research output: Contribution to journalArticlepeer-review

Abstract

We report muon spin relaxation (μSR) and magnetic-susceptibility measurements on Cu (Cl,Br) La (Nb,Ta) 2 O7, which demonstrate: (a) the absence of static magnetism in (CuCl) LaNb2 O7 down to 15 mK confirming a spin-gapped ground state; (b) phase separation between partial volumes with a spin-gap and static magnetism in (CuCl) La (Nb,Ta) 2 O7; (c) history-dependent magnetization in the (Nb,Ta) and (Cl,Br) substitution systems; (d) a uniform long-range collinear antiferromagnetic state in (CuBr) LaNb2 O7; and (e) a decrease in Néel temperature with decreasing Br concentration x in Cu (Cl1-x Brx) LaNb2 O7 with no change in the ordered Cu moment size for 0.33≤x≤1. Together with several other μSR studies of quantum phase transitions in geometrically frustrated spin systems, the present results reveal that the evolution from a spin-gap to a magnetically ordered state is often associated with phase separation and/or a first-order phase transition.

Original languageEnglish (US)
Article number174408
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume80
Issue number17
DOIs
StatePublished - Nov 13 2009
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Muon spin relaxation studies of the frustrated quasi-two-dimensional square-lattice spin system Cu (Cl,Br) la (Nb,Ta) 2 O7: Evolution from spin-gap to antiferromagnetic state'. Together they form a unique fingerprint.

Cite this