The -electron state of the heavy fermion superconductor NpPdAl and the isostructural family

Metoki, Naoto   ; Aczel, A. A.*; Aoki, Dai*; Chi, S.*; Fernandez-Baca, J. A.*; Griveau, J.-C.*; Hagihara, Masato*   ; Hong, T.*; Haga, Yoshinori   ; Ikeuchi, Kazuhiko*; Inamura, Yasuhiro  ; Kamazawa, Kazuya*; Kajimoto, Ryoichi  ; Kitazawa, Hideaki*; Masuda, Takatsugu*; Matsuda, Masaaki*; Nakamura, Mitsutaka   ; Otsuki, Junya*; Pajerowski, D.*; Suzuki, Hiroyuki*; Yamamoto, Etsuji  ; Yamauchi, Hiroki   

Rare earths (4) and actinides (5) provide variety of interesting states realized with competing interactions between the increasing number of electrons. Since crystal field splitting of many-body electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the electron states of heavy electron compounds NpPdAl and actinide and rare earth based iso-structural family.