Tsutsui, Satoshi; Higashinaka, Ryuji*; Nakamura, Raito*; Fujiwara, Kosuke*; Nakamura, Jin*; Kobayashi, Yoshio*; Ito, Takashi; Yoda, Yoshitaka*; Kato, Kazuo*; Nitta, Kiyofumi*; et al.
Hyperfine Interactions, 242(1), p.32_1 - 32_10, 2021/12
Kaneko, Masashi; Watanabe, Masayuki; Miyashita, Sunao*; Nakashima, Satoru*
Hyperfine Interactions, 239(1), p.20_1 - 20_10, 2018/12
We optimized a mixing ratio of exchange energy between pure DFT and exact Hartree-Fock using TPSS exchange-correlation functional to estimate the accurate coordination bonds in f-block complexes by numerically benchmarking with the experimental data of Mssbauer isomer shifts for Eu and Np nuclides. Second-order Douglas-Kroll-Hess Hamiltonian with segmented all-electron relativistically contracted basis set was employed to calculate the electron densities at Eu and Np nuclei, i.e. contact densities, for each five complexes for Eu(III) and Np(IV) systems. We compared the root mean square deviation values of their isomer shifts between experiment and calculation by changing the mixing ratio of Hartree-Fock exchange parameter from 0 to 100 % at intervals of 10 %. As the result, it was indicated that the mixing ratio of 30 and 60 % for Eu and Np benchmark systems, respectively, gives the smallest deviation values. Mulliken's spin population analysis indicated that the covalency in the metal-ligand bonds for both Eu and Np complexes decreases with increasing the Hartree-Fock exchange admixture.
Nakashima, Satoru*; Kaneko, Masashi; Yoshinami, Keisuke*; Iwai, Saki*; Dote, Haruka*
Hyperfine Interactions, 239(1), p.39_1 - 39_15, 2018/12
The present study reveals the on/off of spin-crossover (SCO) phenomenon in assembled Fe(II) complexes bridged by bis(pyridyl) type ligand. Whether SCO phenomenon occurs or not in assembled Fe(II) complexes bridged by bis(pyridyl) type ligand is determined by local structure around iron atom. SCO phenomenon occurs when the coordinating pyridines facing to each other across the iron atom are propeller type, while the phenomenon does not occur when they are parallel type or distorted propeller type. DFT calculation explained that, in the shortening of Fe-pyridine bonds when changing from high-spin state to low-spin state, the pyridines of propeller type can approach the iron atom with smaller steric hindrance than those of parallel and distorted propeller type complexes. The local structure is controlled by introducing methyl substituent and introducing -system, changing SCO phenomenon. And the transition temperature of SCO is also controlled in assembled complexes bridged by 1,2-bis(4-pyridyl)ethane by mixing anionic ligand.
Kaneko, Masashi; Yasuhara, Hiroki*; Miyashita, Sunao*; Nakashima, Satoru*
Hyperfine Interactions, 238(1), p.36_1 - 36_9, 2017/11
We aim to evaluate the validity of density functional calculations to the bonding property for Ru and Os complexes. We performed the benchmarking of theoretical computational method with Ru, Os Mssbauer isomer shifts. As the result, the computational values of the electron densities at nucleus position correlated with the experimental Mssbauer isomer shifts.
Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11
Sato, Wataru*; Komatsuda, Sayaka*; Osa, Akihiko; Sato, Tetsuya; Okubo, Yoshitaka*
Hyperfine Interactions, 237(1), p.113_1 - 113_6, 2016/12
The magnetic hyperfine field and electric field gradient at theCd( Cd) and Cd(In) probe nuclei introduced in a perovskite manganese oxide ( 250 K) were measured for the study of the local magnetism and structure by means of time-differential perturbed angular correlation spectroscopy. In the ferromagnetic phase at 77 K, a very slight supertransferred magnetic hyperfine field (SMHF) ( 0.014 T) combined with a well-defined electric field gradient was observed at the nonmagnetic Cd nucleus on the La/Ca A site. This observation suggests that the large magnetic hyperfine field ( = 6.9 T) measured, in our previous work, at the Ce probe nucleus on the A site originates from the contribution of a 4 spin oriented by the SMHF from adjacent Mn ions.
Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12
Kurokuzu, Masayuki*; Kitao, Shinji*; Kobayashi, Yasuhiro*; Saito, Makina*; Masuda, Ryo*; Mitsui, Takaya; Yoda, Yoshitaka*; Seto, Makoto*
Hyperfine Interactions, 226(1), p.687 - 691, 2014/04
Nakamura, Akio; Igawa, Naoki; Okamoto, Yoshihiro; Wang, J.*; Hinatsu, Yukio*; Takahashi, Masashi*; Takeda, Masuo*
Hyperfine Interactions, 217(1-3), p.17 - 26, 2013/04
Miyabe, Masabumi; Oba, Masaki; Iimura, Hideki; Akaoka, Katsuaki; Maruyama, Yoichiro; Oba, Hironori; Tampo, Motonobu; Wakaida, Ikuo
Hyperfine Interactions, 216(1-3), p.71 - 77, 2013/04
To determine experimental conditions suitable for isotope analysis, we studied the plume dynamics of uranium. A uranium oxide sample was ablated by 2nd harmonic radiation from a Nd:YAG laser at a fluence of 0.5 J/cm. The temporal evolution of the ablation plume was investigated in 800 Pa helium environment. It was found that the observation at 3-510s after the ablation at the height of about 2.5 mm are most suited for obtaining higher sensitivity. Using the established conditions, we obtained the limit of detection of the isotope ratio (U/U) to be 0.01%. In addition, the limit of detection of elemental abundance of uranium in uranium glass was also evaluated.
Mitsui, Takaya; Masuda, Ryo; Hirao, Naohisa*; Mibu, Ko*; Seto, Makoto
Hyperfine Interactions, 204(1-3), p.97 - 100, 2012/04
Nakamura, Akio; imai, kazutaka*; Igawa, Naoki; Okamoto, Yoshihiro; Yamamoto, Etsuji; Matsukawa, Shiro*; Takahashi, Masashi*
Hyperfine Interactions, 207(1-3), p.67 - 71, 2012/03
Masuda, Ryo; Mitsui, Takaya; Ito, Keiji*; Sakaki, Koji*; Enoki, Hirotoshi*; Nakamura, Yumiko*; Seto, Makoto
Hyperfine Interactions, 204(1-3), p.139 - 142, 2012/03
We have been developing a system for in situ Mssbauer studies using synchrotron radiation (SR) to elucidate the mechanism of hydrogenation processes. In the system, samples reacts in an atmosphere chamber and SR-based Mssbauer spectra using variable-frequency nuclear monochromator and energy spectra of inelastic nuclear resonant scattering (NRS) of SR are measured. As a feasibility study, the temperature dependence of the Mssbauer and inelastic NRS spectra of Fe in -GdFeH under vacuum were measured. In both spectra, clear differences were observed between 373 K and 573 K. These differences can be interpreted by the change of microscopic environment around Fe at the dehydrogenation. Thus, it is confirmed that this system works well enough to perform the in-situ Mssbauer study on the dehydrogenation of -GdFeH.
Harami, Taikan*; Kitao, Shinji*; Kobayashi, Yasuhiro*; Mitsui, Takaya
Hyperfine Interactions, 181(1-3), p.179 - 187, 2008/01
The unfolded heme structure in myoglobin is controversial because of no chance of direct X-ray structure analyses. The unfolding of carbonmonoxy myoglobin (MbCO) by guanidine hydrochloride (GdnHCl) was studied by the Mssbauer spectroscopy. The spectra show the presence of a sort of spectrum in the unfolded MbCO, independent on the concentration of GdnHCl from 1 to 6 M and the increase of the fraction of unfolded MbCO, depending on the GdnHCl concentration. The isomer shift of the iron of heme in the unfolded MbCO was identified to be different from that of the native MbCO as the globin structure in Mb collapses under the unfolded conditions. This result and the existing related Mssbauer data proved that the heme in the unfolded MbCO may remain coordinated to the proximal histidine.
Tsutsui, Satoshi*; Nakada, Masami; Nasu, Saburo*; Homma, Tetsuo*; Tokiwa, Yoshifumi; Aoki, Dai*; Wisniewski, P.*; Haga, Yoshinori; Onuki, Yoshichika
Hyperfine Interactions, 141/142(1-4), p.237 - 242, 2002/06
We have determined the distribution of the 5f-quadrupoles and detected the 5f-quadrupole order in the uranium intermetallics, uranium dipnictides and UPd, with Mo"ssbauer spectroscopy. We have declared that the distribution of the 5f-quadrupoles depends on the magnetic sequence in uranium dipnictides. The distribution of the 5f-quadrupole is spherical in UBi, while those are oblate within c-plane in UP, UAs and USb. We have observed the sudden drop of the recoil-free fraction above the transition temperature of the quadrupole order in UPd. The present result suggests the change of the phonon states due to the quadrupole order in this compound.
Tsutsui, Satoshi; Nakada, Masami; Kobayashi, Yasuhiro*; Nasu, Saburo*; Haga, Yoshinori; Onuki, Yoshichika
Hyperfine Interactions, 133(1-4), p.17 - 21, 2001/11
no abstracts in English
Tsutsui, Satoshi; Nakada, Masami; Nasu, Saburo*; Haga, Yoshinori; Homma, Tetsuo; Yamamoto, Etsuji; Okuni, Hitoshi*; Onuki, Yoshichika
Hyperfine Interactions, 126(1-4), p.335 - 340, 2000/07
no abstracts in English
*; Nagamine, Kanetada*; Matsuzaki, Teiichiro*; Ishida, Katsuhiko*; *; Sakamoto, Shinichi*; *; Tanase, Masakazu; Kato, Mineo; Kurosawa, Kiyoyuki; et al.
Hyperfine Interactions, 118(1-4), p.213 - 215, 1999/00
no abstracts in English
Matsuzaki, Teiichiro*; Nagamine, Kanetada*; Ishida, Katsuhiko*; *; *; Tanase, Masakazu; Kato, Mineo; Kurosawa, Kiyoyuki; Hashimoto, Masashi; Sugai, Hiroyuki; et al.
Hyperfine Interactions, 118(1-4), p.229 - 234, 1999/00
no abstracts in English
Matsuzaki, Teiichiro*; Nagamine, Kanetada*; Tanase, Masakazu; Kato, Mineo; Kurosawa, Kiyoyuki; Ishida, Katsuhiko*; *; *; G.H.Eaton*
Hyperfine Interactions, 119(1-4), p.361 - 363, 1999/00
no abstracts in English