O-17 and V-51 NMR for the zigzag spin-1 chain compound CaV2O4

TitleO-17 and V-51 NMR for the zigzag spin-1 chain compound CaV2O4
Publication TypeJournal Article
Year of Publication2008
AuthorsZong X, Suh BJ, Niazi A, Yan JQ, Schlagel DL, Lograsso TA, Johnston DC
Journal TitlePhysical Review B
Date PublishedJan
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000252862200054

V-51 NMR studies on CaV2O4 single crystals and O-17 NMR studies on O-17-enriched powder samples are reported. The temperature dependences of the O-17 NMR linewidth and nuclear spin-lattice relaxation rate give strong evidence for a long-range antiferromagnetic transition at T-N=78 K in the powder. Magnetic susceptibility measurements show that T-N=69 K in the crystals. A zero-field V-51 NMR signal was observed at low temperatures (f approximate to 237 MHz at 4.2 K) in the crystals. The field-swept spectra with the field in different directions suggest the presence of two antiferromagnetic substructures. Each substructure is collinear, with the easy axes of the two substructures separated by an angle of 19(1)degrees, and with their average direction pointing approximately along the b axis of the crystal structure. The two spin substructures contain equal numbers of spins. The temperature dependence of the ordered moment, measured up to 45 K, shows the presence of an energy gap E-G in the antiferromagnetic spin wave excitation spectrum. Antiferromagnetic spin wave theory suggests that E-G/k(B) lies between 64 and 98 K.

Alternate JournalPhys. Rev. B