title: X-ray magnetic circular dichroism of a valence fluctuating state in eu at high magnetic fields.
abstract: X-ray magnetic circular dichroism (XMCD) at the Eu L edge in two compounds exhibiting valence fluctuation, namely EuNi_{2}(Si_{0.18}Ge_{0.82})_{2} and EuNi_{2}P_{2}, has been investigated at high magnetic fields of up to 40 T. A distinct XMCD peak corresponding to the trivalent state (Eu(3+)), whose ground state is nonmagnetic (J = 0), was observed in addition to the main XMCD peak corresponding to the magnetic (J = 7/2) divalent state (Eu(2+)). This result indicates that the 5d electrons belonging to both valence states are magnetically polarized. It was also found that the ratio P_{5d}(3+)/P_{5d}(2+) between the polarization of 5d electrons (P_{5d}) in the Eu(3+) state and that of Eu(2+) depends on the material. The possible origin of the XMCD and an explanation of the material dependence of P_{5d}(3+)/P_{5d}(2+) are discussed in terms of hybridization between the conduction electrons and the f electrons.
authors: Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan. ymatsuda@issp.u-tokyo.ac.jp
authors: Y H
authors: YH
authors: Matsuda
authors: Z W
authors: ZW
authors: Ouyang
authors: H
authors: H
authors: Nojiri
authors: T
authors: T
authors: Inami
authors: K
authors: K
authors: Ohwada
authors: M
authors: M
authors: Suzuki
authors: N
authors: N
authors: Kawamura
authors: A
authors: A
authors: Mitsuda
authors: H
authors: H
authors: Wada