First-Order Kondo-Frustrated Antiferromagnetic Ordering in the Heavy Electron Compound YbAs

摘要

/sup 170/Yb Mossbauer measurements show that the heavy electron compound YbAs undergoes a first order paramagnetic-antiferromagnetic transition centered at T/sub N/ = 0.58K. The saturated 4f-shell magnetic moments are reduced by 47% relative to the value predicted by a crystal field model. A study of the line shapes below T/sub N/ in the presence of an external field shows that the RKKY exchange energy is about 20 times bigger than k/sub B/T/sub N/. These results show that YbAs presents a magnetic order frustrated by the Kondo effect. (ERA citation 13:015252)