Magneto and ferroelectric phase transitions in HoMn2O5 monocrystals

From the physical point of view multiferroics present an extremely interesting class of systems and problems. These are essentially of two kinds. One is what are the microscopic conditions, and sometimes constrains, which determine the possibility to combine in one system both magnetic and ferroelectric properties. This turned out to be a quite nontrivial question, and usually, in conventional systems, these two phenomena tend to exclude one another. Why it is the case is an important and still not completely resolved issue. In the present article we report our results from magnetic properties measurements on HoMn2O5 with short discussion about it possible origin

Frustrated minority spins in GeNi2O4

Recently, two consecutive phase transitions were observed, upon cooling, in an antiferromagnetic spinel GeNi$_2$O$_4$ at $T_{N1}=12.1$ K and $T_{N2}=11.4$ K, respectively \cite{matsuno, crawford}. Using unpolarized and polarized elastic neutron scattering we show that the two transitions are due to the existence of frustrated minority spins in this compound. Upon cooling, at $T_{N1}$ the spins on the \kagome planes order ferromagnetically in the plane and antiferromagnetically between the planes (phase I), leaving the spins on the triangular planes that separate the \kagome planes frustrated and disordered. At the lower $T_{N2}$, the triangular spins also order in the $$ plane (phase II). We also present a scenario involving exchange interactions that qualitatively explains the origin of the two purely magnetic phase transitions

Filled skutterudite structure of europium ruthenium polyphosphide, EuRu4P12

The crystal structure of EuRu4P12 is isotypic with filled skutterudite structures of rare earth transition metal poly­phosphides: RFe4P12 (R = Ce, Pr, Nd, Sm and Eu), RRu4P12 (R = La, Ce, Pr and Nd) and ROs4P12 (R = La, Ce, Pr and Nd). The Ru cation is coordinated by six P anions in a distorted octa­hedral manner. The partially occupied Eu position (site occupancy 0.97) is enclosed by a cage formed by the corner-shared framework of the eight RuP6 octa­hedra

Novel temperature stable high-ε r microwave dielectrics in the Bi 2 O 3 –TiO 2 –V 2 O 5 system

In the present work, a series of low temperature firing (1 − x)BiVO4–xTiO2 (x = 0.4, 0.50, 0.55 and 0.60) microwave dielectric ceramics was prepared using traditional solid state reaction method. From back-scattered electron images (BEI), X-ray diffraction (XRD) and energy dispersive analysis (EDS), there was negligible reaction between BiVO4 and TiO2 at the optimal sintering temperature ∼900 °C. As x increased from 0.4 to 0.60, permittivity (εr) increased from 81.8 to 87.7, quality factor value (Qf) decreased from 12 290 to 8240 GHz and temperature coefficient (TCF) shifted from −121 to +46 ppm per °C. Temperature stable microwave dielectric ceramic was obtained in 0.45BiVO4–0.55TiO2 composition sintered at 900 °C with a εr ∼ 86, a Qf ∼ 9500 GHz and a TCF ∼ −8 ppm per °C. Far-infrared reflectivity fitting indicated that stretching of Bi–O and Ti–O bonds in this system dominated dielectric polarization. This series of ceramics are promising not only for low temperature co-fired ceramic (LTCC) technology but also as substrates for physically and electrically small dielectrically loaded micro-strip patch antennas

Order Parameters and Phase Diagrams of Multiferroics

The symmetry properties, order parameters, and magnetoelectric phase diagrams of multiferroics are discussed. After brief reviews of Ni$_3$V$_2$O$_8$, TbMnO$_3$, and RbFe(MoO$_4$)$_2$, we present a detailed analysis of RMn$_2$O$_5$ (with R=Y, Ho, Dy, Er, Tb, Tm).Comment: 23 pages, 7 figures, 3 tables. For FOCUS ON MULTIFERROICS (IOP

「日本語話し言葉コーパス」における書き起こしの方法とその基準について

国立国語研究所青山学院大学／国立国語研究所東京都立大学／国立国語研究所東京大学／国立国語研究所国立国語研究所国立国語研究所国立国語研究所国立国語研究所,通信総合研究所,東京工業大学では,科学技術振興調整費開放的融合研究制度『話し言葉の言語的・パラ言語的構造の解明に基づく「話し言葉工学」の構築』プロジェクトにおいて,自発性の高い話し言葉の情報処理基盤技術の確立を目標に活動を進めている。現在国立国語研究所では,このプロジェクトの一環として,モノローグを対象とした大規模な日本語話し言葉コーパスを作成している。このコーパスには,約700時間(約700万語に相当)の音声,書き起こしテキスト,および品詞や分節音,韻律などの情報が含まれる予定である。本稿では,本コーパスの書き起こしの方法とその基準について紹介する

リアルタイムMRI動画日本語調音運動データベースの設計

National Institute for Japanese Language and LinguisticsNational Institute for Japanese Language and LinguisticsWaseda UniversityNational Institute for Japanese Language and LinguisticsATR-PromotionsATR-PromotionsChiba Institute of TechnologyKonan UniversityTakushoku UniversityNational Institute for Japanese Language and LinguisticsNational Institute for Japanese Language and LinguisticsWaseda UniversityWaseda UniversityPicolab会議名: 言語資源活用ワークショップ2020, 開催地: オンライン, 会期: 2020年9月8日−9日, 主催: 国立国語研究所 コーパス開発センターわれわれは、日本語に関する調音音声学的研究の新しいインフラ提供をめざして、調音運動データベースの構築を進めてきている。声道全体の形状変化を毎秒14 ないし25 フレームのリアルタイムMRI 動画として記録したデータが、現時点で東京方言16 名、近畿方言5名分収録済である。1 名あたりの発話量は25〜30 分である。データには個々の発話の開始時刻と終了時刻のタグが付与されており、他に発話内容と話者に関するメタデータを検索に利用できる