Order and disorder in the local and long-range structure of the spin-glass pyrochlore, Tb2Mo2O7

摘要: Order and disorder in the local long-range structure of spin-glass pyrochlore, Tb 2 Mo O 7 Yu Jiang 1 , Ashfia Huq Corwin H. Booth Georg Ehlers John E. Greedan 3 Jason S. Gardner 4,5 Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA Neutron Scattering Science Oak Ridge Ridge, TN 37831-6475, Department Chemistry Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1, Canada Physics, Indiana Bloomington, IN 47408, NIST Center NIST, Gaithersburg, MD 20899-6102, E-mail: chbooth@lbl.gov Date: 14 February 2011 Abstract. To understand origin state molybdate pyrochlores, is investigated using two techniques: lattice was measured neutron powder diffraction (NPD), information obtained from extended x-ray absorption fine (EXAFS) technique. While appears generally well ordered, enhanced mean-squared site displacements on O(1) lack temperature dependence strongly anisotropic displacement parameters both sites indicate some exists. Likewise, measurements Mo-Mo Tb-O(1) nearest-neighbor exists, similar to that found related Y . Although freezing 25 K, slightly higher than 22 degree pair distance actually less This apparent contradiction considered light interactions involved process. 1. Introduction The pyrochlore family (A B space group F d 3m, A, at 16d, B, 16c site, representing different transition or rare earth metal ions) has attracted much attention over past few decades.