Magnetic Resonance of Lanthanide Ions as Magnetic Probes in the Antiferromagnetic Phase of Dysprosium Phosphate

M. M. Abraham, J. M. Baker, B. Bleaney, A. A. Jenkins, P. M. Martineau, J. Z. Pfeffer
1991 Proceedings of the Royal Society A  
B y M. M. A b r a h a m *)*, J-M. B a k e r , B. B l e a n e y , A. A. J e n k i n s , P. M. M a r t i n e a u a n d J . Z. P f e f f e r Clarendon L a b o r a t o r y , Parks M easurem ents of electron m agnetic resonance are discussed for im p u rity ions in the antiferrom agnetic host com pound D y P 0 4 (Neel tem p eratu re TN = 3.39 K). This is a simple tw o sublattice an tife rro m a g n e t; the im p u rity ions are Y b 3+ and E r 3+, each w ith a K ram ers doublet as th e ground state.
more » ... esonance is observed a t frequencies of ca. 24 and 34 GHz, and th e angular dependence of th e m agnetic field is fitted to simple theoretical equations. Since th e m agnetic m om ents in the host lattice are ordered, th e resonance lines are relatively narrow , m aking it possible to determ ine th e value of th e intern al field acting on each im p u rity ion. From this, the exchange field is obtained by su b tractin g the value of th e dipolar field generated by the ordered m om ents of th e host ions. Some m easurem ents have been m ade in th e spin flop phase. The values of the exchange field are found n o t to conform to a simple model based on isotropic exchange interaction between th e real electron spins of the lanthanide ions. H yperfine splitting is detected from the odd isotope m Yb, n atu ra l abundance 14% , / = t Permanent address: Oak
doi:10.1098/rspa.1991.0164 fatcat:b6jlxlmbqzfu5n7ni57ofogrle