27Al and 65Cu NMR study in UCu5Al

✍ Scribed by Bogdan Nowak; Robert Troć

• Book ID: 104358025
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 242 KB
• Volume: 14
• Category: Article
• ISSN: 0926-2040
• DOI: 10.1016/s0926-2040(99)00023-5

✦ Synopsis

We have studied the microscopic properties of the tetragonal UCu Al Kondo compound by 27 Al and 63,65 Cu NMR in the 5 paramagnetic state. NMR and susceptibility measurements performed on the powdered sample, but oriented along the Ž . Ž . applied field, showed x ) x . Plots of K T against x T at temperatures T G 100 K yield the transferred hyperfine 5 H 5 5 fields of q5.9 kOerm for 27 Al nuclei, and q5.3 and y7.0 kOerm for 65 Cu nuclei in crystallographically inequivalent B B

Ž . Ž . Cu 2 and Cu 1 sites, respectively. The Knight shift vs. susceptibility plots for T -100 K exhibit a deviation from the Ž . linear behaviour absolute values of shifts become smaller than expected . We attribute this finding to the crystalline electric Ž . field effect in similar way as it was reported for several Ce-based compounds. The random distribution of the Al and Cu 2 atoms in the crystal lattice we consider as a reason of an unusual broadening of the NMR spectra, particularly at low temperatures.