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Kaneko, Koji; Stockert, O.*; Mufti, N.*; Kiefer, K.*; Klingner, C.*; Krellner, C.*; Geibel, C.*; Steglich, F.*
Journal of Physics; Conference Series, 200, p.032031_1 - 032031_4, 2010/02
Times Cited Count:5 Percentile:83.73(Materials Science, Multidisciplinary)Kambe, Takashi*; Komatsu, Takuma*; Michiuchi, Takamasa*; Hayakawa, Hiroki*; Oishi, Daisuke*; Hanasaki, Noriaki*; Yoshii, Kenji; Ikeda, Naoshi*
Journal of Physics; Conference Series, 200, p.012077_1 - 012077_4, 2010/02
Times Cited Count:4 Percentile:79.48(Materials Science, Multidisciplinary)A magneto-electric effect (ME) was observed in a charge-ordered ferroelectric LuFeO
. The dielectric response in a three-dimensional charge-ordered phase is strongly influenced by magnetic field, especially around the ferri-magnetic ordering temperature. We also show the relation between the oxygen stoichiometry and the ME signal character above the magnetic transition temperature.
Matsuo, Yoji*; Mori, Shigeo*; Hirata, Akihiko*; Yoshii, Kenji; Ikeda, Naoshi*
Journal of Physics; Conference Series, 200, p.012128_1 - 012128_4, 2010/02
Times Cited Count:3 Percentile:73.32(Materials Science, Multidisciplinary)RFeO
(R= Ho-Lu,Y) is a novel ferroelectric material in which ferroelectric polarization is caused by the charge ordering (CO) of Fe
and Fe
. In this work we investigated the CO structure and dielectric/magnetic properties in RFe
O
and RFeCuO
(R=Lu,Yb, M=Cu,Co) by a transmission electron microscopy (TEM), combining with dielectric and magnetic measurements. LuFeCuO
is a dielectric compound, which shows the characteristic low-frequency dielectric dispersion. In addition, the Cu
substitution in LuFe
O
suppressed the formation of the CO structure and induced characteristic polar nanodomains with the 5-10nm size. Magnetic measurement revealed that LuFeCuO
shows the magnetic transition around 50K, which is much lower than the magnetictransition temperature of 250K in LuFe
O
. Our experimental results suggest that the polar nanodomains should be responsible for the magnetic/dielectric properties in RFeMO
.
Kambe, Shinsaku; Sakai, Hironori; Tokunaga, Yo; Matsuda, Tatsuma; Haga, Yoshinori; Yasuoka, Hiroshi; Chudo, Hiroyuki; Walstedt, R. E.*
Journal of Physics; Conference Series, 200, p.012076_1 - 012076_4, 2010/02
Times Cited Count:1 Percentile:45.56(Materials Science, Multidisciplinary)In order to clarify quantum criticality in heavy fermion systems, we propose to use the Gaussian spin-echo decay rate of the NMR spin-spin relaxation. In contrast to the spin-lattice relaxation rate
, which is connected with the dynamical susceptibility Im
,
is driven by the static susceptibility Re
at finite
for an antiferromagnet. The combined quantity
is found to provide key information in determining the nature of quantum criticality. The
-dependence of
for the Sn site in the heavy fermion compound USn
is presented as an example.
Mori, Shigeo*; Yoshidome, Kazuhiro*; Nagamine, Yuki*; Togawa, Yoshihiko*; Yoshii, Kenji; Takenaka, Koshi*
Journal of Physics; Conference Series, 200, p.012129_1 - 012129_4, 2010/02
Times Cited Count:5 Percentile:83.73(Materials Science, Multidisciplinary)Doping effect on ferromagnetic (FM) properties in perovskite manganites LaSr
MnO
(x=0.175) were investigated by low-temperature Lorentz transmission electron microscopy (TEM), in combination with the conventional magnetic measurements. It is found that La
Sr
Mn
Al
O
exhibits a structural phase transition from the rhombohedral to orthorhombic structures at Ts
116 K. During the rhombohedral-to-orthorhombic transition, the FM domain structures changed from the macroscopic FM domains to the FM ones with the wavy stripe pattern. The ac magnetic measurements also revealed that La
Sr
Mn
Al
O
shows unconventional magnetic behaviour at low temperature below 65 K. Partial substitution of non-magnetic Al
for Mn
has some influence on magnetic ordering and double-exchange interaction, which should induce insulator behaviour in the orthorhombic phase.
Hiraka, Haruhiro*; Wakimoto, Shuichi; Takeda, Masayasu; Kakurai, Kazuhisa; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Yamada, Kazuyoshi*
Journal of Physics; Conference Series, 200, p.012059_1 - 012059_4, 2010/02
Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)We studied Fe-dopant effects on spin correlations in BiPb
Sr
CuO
. Magnetic neutron elastic scattering, which is absent in a pristine sample, has been observed at incommensurate positions with an incommensurability of
0.2. Surprisingly, this anomalously large
follows a linear relation
even in the overdoped region, unlike for La
Sr
CuO
. We discuss this specific feature observed in the overdoped phase from a dynamical stripe viewpoint.
Chudo, Hiroyuki; Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Aoki, Dai*; Haga, Yoshinori; Matsuda, Tatsuma; Homma, Yoshiya*; Nakano, Yasunori*; Honda, Fuminori*; et al.
Journal of Physics; Conference Series, 200, p.012020_1 - 012020_4, 2010/02
Times Cited Count:3 Percentile:73.32(Materials Science, Multidisciplinary)We report the results of Pd NQR experiments on NpPd
Al
and CePd
Al
. In the normal state at 6 K, the
Pd NQR spectrum consists of four lines in both systems. These lines can be assigned to two sets of
and
NQR transitions arising from two crystallographically in equivalent Pd sites. From the analysis of the
Pd NQR spectrum the nuclear quadrupole frequency
, asymmetry parameter
and electric field gradient
have been deduced.
Sakai, Toru; Okamoto, Kiyomi*; Tonegawa, Takashi*
Journal of Physics; Conference Series, 200, p.022052_1 - 022052_4, 2010/02
Times Cited Count:4 Percentile:79.48(Materials Science, Multidisciplinary)The distorted diamond chain has attracted a lot of interest, since the compound Cu(CO
)
(OH)
, so-called azurite, was revealed to be a good candidate for this system. Although several theoretical studies were performed, the strong anisotropy observed in the magnetization measurement of azurite has not been explained very well. To solve the mechanism of this anisotropy, we introduce the Dzyaloshinsky-Moriya (DM) interaction suitable for the crystal symmetry of azurite. The numerical diagonalization study on this realistic model indicates that the anisotropy in the experimental magnetization curve would be reproduced with sufficiently large DM interaction.
Inami, Toshiya; Terada, Noriki*; Kitazawa, Hideaki*; Sakai, Osamu*
Journal of Physics; Conference Series, 200, p.032022_1 - 032022_4, 2010/02
Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)Igarashi, Ryo; Ogata, Masao*
Journal of Physics; Conference Series, 200, p.022019_1 - 022019_4, 2010/02
Times Cited Count:1 Percentile:45.56(Materials Science, Multidisciplinary)Matsuda, Tatsuma; Haga, Yoshinori; Aoki, Dai*; Homma, Yoshiya*; Tateiwa, Naoyuki; Yamamoto, Etsuji; Onuki, Yoshichika
Journal of Physics; Conference Series, 200, p.012113_1 - 012113_4, 2010/02
Times Cited Count:2 Percentile:63.59(Materials Science, Multidisciplinary)The anisotropic superconductor NpPdAl
with ZrNi
Al
-type tetragonal structure was studied by means of electrical resistivity and Hall effect in the normal state. The temperature dependence of electrical resistivity
shows a large anisotropic behavior. The resistivity for
[001] is larger than that for
[100] in the whole temperature region. At high temperatures
is proportional to
, which is characteristic behavior in Kondo effect. The field dependence of Hall resistivity
shows a linear dependence up to 55 kOe with a large slope for the field. The slope of
for field along
-axis is negative, but for field along
-axis, the slope dramatically changed from negative to positive with increasing temperature.
Onishi, Hiroaki
Journal of Physics; Conference Series, 200, p.012152_1 - 012152_4, 2010/02
Times Cited Count:2 Percentile:63.59(Materials Science, Multidisciplinary)Takeda, Yukiharu; Okane, Tetsuo; Okochi, Takuo*; Fujimori, Shinichi; Saito, Yuji; Yamagami, Hiroshi; Yabuta, Hisato*; Takabatake, Toshiro*
Journal of Physics; Conference Series, 200, p.012199_1 - 012199_4, 2010/02
Times Cited Count:3 Percentile:73.32(Materials Science, Multidisciplinary)no abstracts in English
Takeda, Masayasu; Endo, Yasuo; Onose, Yoshinori*; Kakurai, Kazuhisa; Suzuki, Junichi; Tokura, Yoshinori*
no journal, ,
Complex phase transition of magnetic long range order in FeCo
Si has been investigated by small-angle neutron scattering (SANS) measurements. We found liquidcrystal-like behavior of the magnetic textures under external magnetic fields. A variety of the scattering patterns, ring, crescent-shape, diffusive spots etc. appeared by changing temperatures and applying magnetic fields. This behavior can be explained by an analogy of the phase transition of the liquid crystal when the net magnetization of the conical state under the magnetic fields is regarded as the director of the liquid crystals.
Kawana, Daichi; Watanuki, Tetsu; Machida, Akihiko; Shobu, Takahisa; Aoki, Katsutoshi; Tsai, A. P.*
no journal, ,
no abstracts in English
Fujimori, Shinichi; Okochi, Takuo*; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Aoki, Dai*; Yamamoto, Etsuji; Onuki, Yoshichika; Haga, Yoshinori
no journal, ,
Uranium nitride (UN) is a type I antiferromagnet with Nel temperature
=53 K. Since U-U distance in this compound (3.46
) is close to the Hill limit (3.4
), nature of U 5
electrons has been debated so far between localized and itinerant states. Recently, it has been suggested that the U 5
electrons in this compound have dual (itinerant and localized) characters. We have studied Fermi surface and band structure of single crystal UN by angle resolved photoelectron spectroscopy (ARPES) to understand the nature of U 5
states. In contrast to the previous ARPES results, quasi-particle bands originated from U 5
states were clearly observed in the present ARPES spectra. The obtained Fermi surface as well as band structure were well explained by the band structure calculation treating all U 5
electrons as being itinerant. We have found that U 5
electrons in this compound are very itinerant, and the antifferomagnetism in this compound is an itinerant origin.
Akiya, Takahiro*; Takeda, Masayasu; Suzuki, Junichi; Yamaguchi, Daisuke; Kato, Hiroaki*
no journal, ,
In spite of tremendous efforts, a role of intergranular Nd-rich phase in sintered Nd-Fe-B magnets on the coercivity () seems to be still unclear. The purpose of this work is to perform small-angle neutron scattering experiments on the sintered Nd-Fe-
B magnets with different
values and to investigate whether there exists any correlation between the average structure and the magnitude of
. We found that the value of characterized intensity
did not depend on the
when
is parallel to the
-axis of the main Nd
Fe
B grain. On the other hand, for the
configuration, we found that log
linearly increases with increasing
, for five different samples with
ranging from 13 to 16 kOe owing to different annealing conditions.
Jarrige, I.; Rueff, J.-P.*; Shieh, S.*; Taguchi, Munetaka*; Oishi, Yasuo*; Matsumura, Takeshi*; Ishii, Hirofumi*; Hiraoka, Nozomu*; Cai, Y. Q.*
no journal, ,
Takeda, Yukiharu; Okane, Tetsuo; Okochi, Takuo*; Fujimori, Shinichi; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi*; Ikeda, Shugo*; Sakai, Hironori; Haga, Yoshinori; et al.
no journal, ,
no abstracts in English
Agui, Akane; Mizumaki, Masaichiro*
no journal, ,
no abstracts in English