Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Yoshii, Kenji; Funae, Takeshi*; Mizumaki, Masaichiro*; Ejiri, Hiroki*; Ikeda, Naoshi*; Saito, Hiroyuki; Matsumura, Daiju
Physica Status Solidi (C), 12(6), p.841 - 844, 2015/06
Times Cited Count:1 Percentile:40.68(Physics, Condensed Matter)We report the effects of elemental substitutions in multiferroic FeO (: Y, Ho-Lu, In). The substitution by nonmagnetic Ga at the Fe site, which has not been reported so far, shows a drastic decrease in the ferrimagnetic transition temperature (). This is plausibly owing to the suppression of magnetic interactions between Fe ions, based on our previous results of other substituted systems such as FeCoO. Dielectric constants near room temperature were comparable to those of FeO. The suppression of dielectric loss in this system is suitable to application. The -site substitution was also attempted by the large R ions such as Dy. The solubility limit was up to about 10% of ions, as confirmed by XRD and EXAFS measurements. was raised by 5-10 K for Dy substitution.
Maeda, Daisuke*; Fukuyama, Ryota*; Kitamura, Satoshi*; Funae, Takeshi*; Matsuo, Yoji*; Ikeda, Naoshi*; Kambe, Takashi*; Kimizuka, Noboru*; Yoshii, Kenji
no journal, ,
We have investigated the successive phase transition in YFeO, which shows charge-ordering-induced ferroelectricity below about 330 K. This material has been reported to show complex phase transitions below 330 K. In this work we have studied the structure and physical properties of YFeO synthesized in a variety of preparation conditions, and have found that slight changes of the conditions led to drastic alternations of physical properties. Details of the results will be shown at the conference.
Oishi, Daisuke*; Hayakawa, Hironori*; Akahama, Yuji*; Funae, Takeshi*; Matsuo, Yoji*; Ikeda, Naoshi*; Kambe, Takashi*; Kimizuka, Noboru*; Yoshii, Kenji
no journal, ,
We have investigated the multiferroic behavior and the magnetic phase diagram of single-crystalline electronic ferroelectric LuFeO. Dielectric measurements under an applied magnetic field showed large magneto-capacitance at around room temperature. A complex magnetic phase diagram was obtained from detailed magnetic measurements below about room temperature. More details will be shown at the conference.
Fukuyama, Ryota*; Yoshii, Kenji; Kuroda, Tomoko*; Kitamura, Satoshi*; Funae, Takeshi*; Matsuo, Yoji*; Ikeda, Naoshi*; Kimizuka, Noboru*; Kambe, Takashi*
no journal, ,
We have investigated the physical properties of LuFeO, which has a related structure to the electronic ferroelectric RFeO (R: rare earths). Magnetic measurements showed that its magnetic transition temperature was about 260-270 K. Dielectric measurements showed that dielectric constants at room temperature were about 10000. This material also showed a magneto-dielectric effect at around room temperature, a result which is interesting from the viewpoints of both fundamental and applied science.
Hoshiyama, Takuya*; Mori, Shigeo*; Matsuo, Yoji*; Funae, Takeshi*; Kambe, Takashi*; Ikeda, Naoshi*; Kimizuka, Noboru*; Yoshii, Kenji; Michiue, Yuichi*
no journal, ,
We have investigated the crystal structure and physical properties of RFeTiO(R=Lu,Yb). The samples were prepared by the solid-state reaction method in air. X-ray and electron diffraction measurements showed that the materials have the same crystal structure as that of multiferroic RMnO. Magnetic measurements showed the absence of magnetic transition below 400 K. Dielectric measurements showed the peak of dielectric constant above room temperature, suggesting a existence of ferroelectric phase transition at high temperatures.
Yoshii, Kenji; Matsumura, Daiju; Endo, Naruki; Saito, Hiroyuki; Yoneda, Yasuhiro; Nishihata, Yasuo; Funae, Takeshi*; Ejiri, Hiroki*; Kano, Jun*; Kobayashi, Tatsuo*; et al.
no journal, ,
We have investigated the substitution effects at the rare-earth (R) site in multiferroic RFeO (R: Y, Ho-Lu) to explore a new phase of this system. From EXAFS measurements for the R atoms, the large R ions (such as Dy) was partially substituted in RFeO. Powder X-ray diffraction showed that this material had a single-phase RFeO-type structure (space group R-3m). The simulated EXAFS spectrum reproduced the characteristics of the experimental spectrum, confirming that R is actually settled at the rare earth site. The other results, such as the magnetic properties, will be reported at the conference.