Probing the f-state configuration of URu2Si2 with U LIII-edge resonant x-ray absorption spectroscopy

Medling, S. A.¹  Booth, C. H.¹  Tobin, J. G.²  Baumbach, R. E.³  Bauer, E. D.³  Sokaras, D.⁴  Nordlund, D.⁴  Weng, T. C.⁴ 

[1] Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States);Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States);Los Alamos National Lab. (LANL), Los Alamos, NM (United States);SLAC National Accelerator Lab., Menlo Park, CA (United States)

关键词: ABSORPTION SPECTROSCOPY;    F STATES;    X-RAY SPECTROSCOPY;    ENTROPY;    EMISSION SPECTROSCOPY;    ORDER PARAMETERS;    PHASE TRANSFORMATIONS;    ANTIFERROMAGNETISM;    MAGNETIC MOMENTS;    TEMPERATURE RANGE 0013-0065 K;    URANIUM SILICIDES;    RUTHENIUM SILICIDES;   

DOI  :  10.2172/1240934
RP-ID  :  LLNL--TR-678981
PID  :  OSTI ID: 1240934
Others  :  TRN: US1600691

学科分类：凝聚态物理

美国|英语

来源: SciTech Connect

【 摘 要 】

It has often been said that the most interesting physics occurs when competing interactions are of nearly the same magnitude. Such a situation is surely occurring at URu₂Si₂???s so-called ???hidden-order transition???, which garners its name from the missing entropy at a 17.5 K phase transition relative to that expected for a conventional antiferromagnetic phase transition, despite the presence of only a very small ordered magnetic moment. Despite this discrepancy being identified in 1985, the identification of the order parameter remains elusive, although progress toward understand- ing this transition has been steady since that time, and URu₂Si₂ remains an important research subject today. The work described provides measures of the 5f orbital occupancy and itinerancy using resonant x-ray emission spectroscopy (RXES) at the U L_III absorption edge and measuring U L_??1 emission that potentially acts as a dividing line between different classes of ???hidden-order??? theories.