Systematic changes of the electronic structure of the diluted ferromagnetic oxide Li-doped NiFeO with hole doping

Kobayashi, Masaki*; Hwang, J. I.*; Song, G.*; Oki, Yasuhiro*; Takizawa, Masaru*; Fujimori, Atsushi; Takeda, Yukiharu; Fujimori, Shinichi; Terai, Kota*; Okane, Tetsuo; et al.

Physical Review B, 78(15), p.155322_1 - 155322_4, 2008/10

https://doi.org/10.1103/PhysRevB.78.155322

X-ray magnetic circular dichroism and photoemission studies of ferromagnetism in CaMnRuO thin films

Terai, Kota*; Yoshii, Kenji; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Owada, Kenji; Inami, Toshiya; Okane, Tetsuo; Arita, Masashi*; Shimada, Kenya*; et al.

Physical Review B, 77(11), p.115128_1 - 115128_6, 2008/03

https://doi.org/10.1103/PhysRevB.77.115128

Soft X-ray magnetic circular dichroism study of CaSrRuO across the ferromagnetic quantum phase transition

Okamoto, Jun*; Okane, Tetsuo; Saito, Yuji; Terai, Kota*; Fujimori, Shinichi; Muramatsu, Yasuji*; Yoshii, Kenji; Mamiya, Kazutoshi*; Koide, Tsuneharu*; Fujimori, Atsushi; et al.

Physical Review B, 76(18), p.184441_1 - 184441_5, 2007/11

https://doi.org/10.1103/PhysRevB.76.184441

CaSrRuO, which is ferromagnetic for Sr concentration x 0.3, has been studied by X-ray magnetic circular dichroism (XMCD) in Ru 3 and O 1 core-level X-ray absorption. XMCD signals appear at x 0.3 and monotonically increases with x in the ferromagnetic phase. While the monotonic increase of the XMCD signals with x is of a typical Stoner-type, the absence of appreciable change in the spectral line shapes of both the Ru 3 and O 1 XMCD spectra indicate that the itinerant-electron ferromagnetism in CaSrRuO is influenced by strong electron correlation.

Electronic structure and magnetism of CaMnRuO thin films

Terai, Kota; Yoshii, Kenji; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Owada, Kenji; Inami, Toshiya; Okane, Tetsuo; Arita, Masashi*; Shimada, Kenya*; et al.

Journal of Magnetism and Magnetic Materials, 310(2, Part2), p.1070 - 1072, 2007/03

We have studied the electronic and magnetic properties of epitaxially grown CaMnRuO (x = 1.0, 0.5) thin films by X-ray magnetic circular dichroism (XMCD) and hard X-ray photoemission spectroscopy (HXPES). The XMCD studies indicated that the spin moments of Mn and Ru are aligned in the opposite directions. The HXPES spectra indicated the Ru 4d states at around the Fermi edge (E) and the Mn 3d states below E. From these results, we propose that the localized Mn 3d t states and the itinerant Ru 4d t band are antiferromagnetically coupled and give rise to ferromagnetism, in analogy with the mechanism proposed for the double perovskite oxides such as SrFeMoO.

Band structure and fermi surface of uranium compounds; Soft X-ray angle-resolved photoemission study

Fujimori, Shinichi; Terai, Kota; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke; Fujimori, Atsushi; Yamagami, Hiroshi*; Ikeda, Shugo; Matsuda, Tatsuma; et al.

Journal of the Physical Society of Japan, 75(Suppl.), p.99 - 101, 2006/08

https://doi.org/10.1143/JPSJS.75S.99

In the present study, we have performed SX-ARPES experiments on some heavy Fermion (HF) uranium compounds such as UPdAl using soft X-ray synchrotron radiation from BL23SU of SPring-8. UPdAl is an HF uranium compound which has transitions into an antiferromagnetic phase at K and into a superconducting phase at =2 K. To describe the various properties of this compound, the dual model for U 5 states is proposed. In this model, two of the three U 5f states are in a localized state while the third electron has delocalized character. We have obtained U 5f sensitive band structure of UPdAl by SX-ARPES, and the results are compared with this scenario. Temperature dependence of the U 5 electronic structure in this compound is also discussed.

Soft X-ray synchrotron radiation photoemission study on uranium compounds

Fujimori, Shinichi; Terai, Kota; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Muramatsu, Yasuji; Fujimori, Atsushi; Yamagami, Hiroshi*; Ikeda, Shugo; Matsuda, Tatsuma; et al.

Physica B; Condensed Matter, 378-380, p.995 - 996, 2006/05

https://doi.org/10.1016/j.physb.2006.01.506

Recently, photoemission experiments in soft X-ray region have attracted much attention due to their high sensitivities for bulk electronic structures of strongly correlated electron system. We have carried out the high-resolution photoemission experiments on some uranium compounds using soft X-ray synchrotron radiation from SPring-8 to understand their electronic structures. Bulk- and U 5-sensitive band structure and Fermi surface were obtained for itinerant U 5 compounds UFeGa and USb, and they are compared with the results of the band structure calculations treating U 5 states as being itinerant. In addition, we show the results of photoemission study on some heavy fermion compounds such as UPdAl and UNiAl. The temperature dependences of the U 5 electronic structure of UPdAl will be also reported.

Soft X-ray magnetic circular dichroism study of ferromagnetism in CaMnRuO thin films

Terai, Kota; Okane, Tetsuo; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Yoshii, Kenji; Kobayashi, Keisuke*; Fujimori, Atsushi

no journal, , 

A pseudobinary alloy of CaMnRuO (CMRO) is interesting because the solid solution CMRO shows a metallic ferromagnetism although both of the end compositions does not show ferromagnetism. We have fabricated the epitaxial CMRO thin films using the pulsed laser deposition (PLD) method, and studied the ferromagnetic moments by soft X-ray absorption magnetic circular dichroism (XMCD) measurements. The XMCD studies indicated that the spin moments of Mn and Ru are aligned in antiparallel directions. We consider that the small total magnetic moment of CMRO results from the cancellation of the Ru spin moment from Mn spin moment.

Soft X-ray magnetic circular dichroism study of the ferromagnetism in CaMnRuO

Terai, Kota; Okane, Tetsuo; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Yoshii, Kenji; Owada, Kenji; Inami, Toshiya; Arita, Masashi*; Shimada, Kenya*; et al.

no journal, , 

no abstracts in English