Antiferromagnetic bipolar semiconductor LaMnPO with ZrCuSiAs-type structure

Yanagi, Hiroshi*; Watanabe, Takumi*; Kodama, Katsuaki; Iikubo, Satoshi*; Shamoto, Shinichi; Kamiya, Toshio*; Hirano, Masahiro*; Hosono, Hideo*

Journal of Applied Physics, 105(9), p.093916_1 - 093916_8, 2009/05

https://doi.org/10.1063/1.3124582

Electronic and magnetic properties of a layered compound LaMnPO are examined in relation to a newly discovered iso-structural superconductor LaFeAs(P)O. Neutron diffraction measurements, together with temperature dependent magnetic susceptibility, clarify that LaMnPO is an antiferromagnet at least up to 375 K. The spin moment of a Mn ion is determined to be 2.26 at room temperature, and the spin configuration is antiparallel in the Mn-P plane and parallel to between the Mn-P planes, which is rather different from that of LaFeAsO. Optical absorption spectra, photoemission spectra, and temperature dependent electrical conductivity indicate that LaMnPO is a semiconductor. Furthermore, nominally undoped LaMnPO exhibits -type conduction while the conduction type is changed by doping of Cu or Ca to the La sites, indicating that LaMnPO is a bipolar conductor. Density functional calculation using the GGA+U approximation supports the above conclusions; the electronic band structure has an open band gap and the antiferromagnetic spin configuration is more stable than the ferromagnetic one.

Study on the Influence of Groundwater Behavior by Activity of Fault

Furuya, Kazuo*; Kodama, Toshio*

JNC TJ7420 2005-039, 260 Pages, 1999/03

JNC-TJ7420-2005-039.pdf:16.01MB

This report presents the result of literature study of hydrological data on fault and related data, and two-dimensional saturated-unsaturated seepage flow analysis of groundwater behavior around Nojima fault in northwestern part of the Awaji Island after the Hyogoken-Nanbu earthquake in order to study the change of groundwater environment by activity of fault.

None

Furuya, Kazuo*; Kodama, Toshio*

PNC TJ7705 98-001, 367 Pages, 1998/03

PNC-TJ7705-98-001.pdf:19.31MB

None

Proving test on reliability PWR fuel assemblies

; Okubo, Tadatsune*; ; ; Kodama, Toshio; Yamaki, Jikei; ; ; ; ; et al.

Nihon Genshiryoku Gakkai-Shi, 31(10), p.1129 - 1143, 1989/10

https://doi.org/10.3327/jaesj.31.1129

no abstracts in English