Spin-lattice coupling and orbital moment in frustrated magnetic system

• Project/Area Number: 20740209
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: National Institute for Materials Science
• Principal Investigator: TERADA Noriki National Institute for Materials Science, 量子ビームセンター, 研究員 (60442993)
• Project Period (FY): 2008 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2010: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2009: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2008: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: フラストレーション / マルチフェロイクス / 交差相関 / 三角格子 / スピン格子結合

Research Abstract

Novel Cross-correlated phenomena in frustrated antiferromagnet CuFeO_2

Research Products

• [Journal Article] Suppression of Long Range Magnetic Order in the Triangular Lattice Antiferromagnet CuFeO_2 (2011)
  • Author(s): N.Terada, T.Osakabe, H.Kitazawa High-Pressure
  • Journal Title: Phys.Rev.B 83
  • Peer Reviewed
• [Journal Article] Spin-wave spectrum in 'single-domain' magnetic ground state of triangular lattice antiferromagnet CuFeO_2 (2011)
  • Author(s): T.Nakajima, S.Mitsuda, T.Haku, J.Shibata, K.Yoshitomi, Y.Noda, N.Aso, Y.Uwatoko, N.Terada
  • Journal Title: J.Phys.Soc.Jpn. 80 Pages: 14714-14714
  • Peer Reviewed
• [Journal Article] High-Pressure Suppression of Long Range Magnetic Order in the Triangular Lattice Antiferromagnet CuFeO_2 (2011)
  • Author(s): Noriki Terada
  • Journal Title: Physical Review B Volume: 83
  • Peer Reviewed
• [Journal Article] Spin-wave spectrum in 'single-domain' magnetic ground state of triangular lattice antiferromagnet CuFeO_2 (2011)
  • Author(s): Taro Nakajima
  • Journal Title: Journal of Physical Society of Japan Volume: 80
  • Peer Reviewed
• [Journal Article] Charge disproportionation associated with spin ordering in delafossite delafossite CuFeO_2 as seen via resonant x-ray diffraction (2010)
  • Author(s): N.Terada, T.Nakajima, S.Mitsuda, Y.Tanaka, H.Mamiya, H.Kitazawa
  • Journal Title: Phys.Rev.B 81 Pages: 64424-64424
  • Peer Reviewed
• [Journal Article] Exchange-striction associated with the elliptical proper helical magnetic structure in the ferroelectric phase of CuFe_1-yGa_yO_2 (2010)
  • Author(s): N.Terada, T.Nakajima, S.Mitsuda, M.Matsuda, K.Kakurai, Y.Tanaka, H.Kitazawa
  • Journal Title: J.Phys.Conference Series 211 Pages: 12005-12005
  • Peer Reviewed
• [Journal Article] Dielectric relaxation in a nonferroelectric phase of magnetoelectric multiferroic CuFeO_2 (2010)
  • Author(s): S.Mitsuda, M.Yamano, K.Kuribara, T.Nakajima, K.Masuda, K.Yoshitomi, N.Terada, H.Kitazawa, K.Takenaka, T.Takamasu
  • Journal Title: J.Phys.Conference Series 200 Pages: 12120-12120
  • Peer Reviewed
• [Journal Article] High-field/multi-frequency ESR measurements on the triangular lattice antiferromagnet CuFeO_2 (2010)
  • Author(s): S.Kimura N.Nishihagi, H.Yamaguchi, T.Kashiwagi, M.Hagiwara, N.Terada, K.Kindo
  • Journal Title: J.Low Temp.Phys. 159 Pages: 80-80
  • Peer Reviewed
• [Journal Article] Exchange-striction associated with the elliptical proper helical magnetic structure in the ferroelectric phase of CuFe_<1-y>Ga_yO_2 (2010)
  • Author(s): Noriki Terada
  • Journal Title: Journal of Physics : Conference Series Volume: 211
  • Peer Reviewed
• [Journal Article] High-field/multi-fresuency ESR measurements on the triangular lattice antiferromagnet CuFeO_2 (2010)
  • Author(s): Shojiro Kimura
  • Journal Title: Journal of Low Temperature Physics Volume: 159 Pages: 80-83
  • Peer Reviewed
• [Journal Article] Charge disproportionation associated with spin ordering in delafossite delafossite CuFeO_2 as seen via resonant x-ray diffraction (2010)
  • Author(s): Noriki Terada
  • Journal Title: Physical Review B 81
  • Peer Reviewed
• [Journal Article] Electric polarization memory effect in a magnetoelectric multiferroic CuFe_<1-x>Ga_xO_2 (2010)
  • Author(s): Setsuo Mitsuda
  • Journal Title: Physica B 404
  • Peer Reviewed
• [Journal Article] Dielectric relaxation in a nonferroelectric phase of magnetoelectric multiferroic CuFeO_2 (2010)
  • Author(s): Setsuo Mitsuda
  • Journal Title: Journal of Physics : Conference Series 200
  • Peer Reviewed
• [Journal Article] Electric polarization memory effect in a magnetoelectric multiferroic CuFe_1-xGaxO_2 (2009)
  • Author(s): S.Mitsuda N.Nishihagi, H.Yamaguchi, T.Kashiwagi, M.Hagiwara, N.Terada, K.Kindo
  • Journal Title: Physica B 404
  • Peer Reviewed
• [Journal Article] Magnetic phase diagram of multiferroic delafossite CuFe_1-yGayO_2 (2009)
  • Author(s): N.Terada T.Nakajima, S.Mitsuda, H.Kitazawa
  • Journal Title: J.Phys.Conference Series 145 Pages: 12071-12071
  • Peer Reviewed
• [Journal Article] Comprehensive study on ferroelectricity induced by a proper-screw type magnetic ordering in multiferroic CuFeO_2 : Nonmagnetic impurity effect on magnetic and ferroelectric order (2009)
  • Author(s): T.Nakajima, S.Mitsuda, K.Takahashi, M.Yamano, K.Masuda, H.Yamazaki K.Prokes, K.Kiefer, S.Gerischer, N.Terada H.Kitazawa, M.Matauda, K.Kakurai, H.Kimura, Y.Noda, M.Soda, M.Matsuura, K.Hirota
  • Journal Title: Phys.Rev.B 79 Pages: 214423-214423
  • Peer Reviewed
• [Journal Article] Comprehensive study on ferroelectricity induced by a proper-screw type magnetic ordering in multiferroic CuFeO_2 : Nonmagnetic impurity effect on magnetic and ferroelectric order (2009)
  • Author(s): Taro Nakajima
  • Journal Title: Physical Review B 79
  • Peer Reviewed
• [Journal Article] Magnetic phase diagram of multiferroic delafossite CuFe1-yGayO2 (2009)
  • Author(s): Noriki Terada
  • Journal Title: Journal of Physics: Conference Series 145
  • Peer Reviewed
• [Journal Article] Ga-substitution-induced single ferroelectric phase in multiferroic CuFeO_2 (2008)
  • Author(s): N.Terada, T.Nakajima, S.Mitsuda, H.Kitazawa, K.Kaneko, N.Metoki
  • Journal Title: Phys.Rev.B 78 Pages: 14101-14101
  • Peer Reviewed
• [Journal Article] Podlesnyak Identification of microscopic spin-polarization coupling in the ferroelectric phase of magnetoelectric multiferroic CuFe_1-xAlxO_2 (2008)
  • Author(s): T.Nakajima, S.Mitsuda, T.Inami, N.Terada, H.Ohsumi, K.Prokes, A.
  • Journal Title: Phys.Rev.B 78 Pages: 24106-24106
  • Peer Reviewed
• [Journal Article] Electric Polarization Induced by Proper Helical Magnetic Ordering in Delafossite Multiferroic CuFe_1-x AlxO_2 (2008)
  • Author(s): T.Nakajima, S.Mitsuda, S.Kanetsuki, K.Tanaka, K.Fujii, N.Terada, M.Soda, M.Matsuura, K.Hirota
  • Journal Title: Phys.Rev.B 77
  • Peer Reviewed
• [Journal Article] Field-induced Incommensurate Lattice Modulations in the Delafossite CuFeO2 (2008)
  • Author(s): N.Terada, S.Mitsuda, Y.Tanaka, Y.Tabata, K.Katsumata, A.Kikkawa
  • Journal Title: J.Phys.Soc.Jpn. 77
  • NAID: 130005436411
  • Peer Reviewed
• [Journal Article] Ga-substitution-induced single ferroelectric phase in multiferroic CuFeO2 (2008)
  • Author(s): Noriki Terada
  • Journal Title: Physical Review B 78
  • Peer Reviewed
• [Journal Article] Identification of microscopic spin-polarization coupling in the ferroelectric phase of magnetoelectric multiferroic CuFe1-xAlxO2 (2008)
  • Author(s): Taro Nakajima
  • Journal Title: Physical Review B 78
  • Peer Reviewed
• [Presentation] 磁性誘電マルチフェロイックCuFeO_2の常誘電相における電場記憶効果 (2011)
  • Author(s): 山崎裕恵, 中島多朗, 満田節生, 柴田浩平, 竹端寛治, 高増正, 寺田典樹, 北澤英明
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 新潟大学
  • Year and Date: 2011-03-26
• [Presentation] スピン誘導型強誘電体CuFe_1-xGaxO_2における電気分極の一軸応力制御 (2011)
  • Author(s): 吉冨啓祐, 金子周史, 山崎裕恵, 中島多朗, 満田節生, 小坂昌史, 阿曽尚文, 上床美也, 野田幸男, 松浦直人, 寺田典樹, 脇本秀一, 武田全康, 加倉井和久
  • Organizer: 日本物理学会年次大学
  • Place of Presentation: 新潟大学
  • Year and Date: 2011-03-26
• [Presentation] 磁性誘電マルチフェロイックCuFeO_2の常誘電相における電場記憶効果 (2011)
  • Author(s): 山崎裕恵
  • Organizer: 日本物理学会春季大会
  • Place of Presentation: 新潟大学
  • Year and Date: 2011-03-26
• [Presentation] スピン誘導型強誘電体CuFe_<1-x>Ga_xO_2における電気分極の一軸応力制御 (2011)
  • Author(s): 吉冨啓祐
  • Organizer: 日本物理学会春季大会
  • Place of Presentation: 新潟大学
  • Year and Date: 2011-03-26
• [Presentation] CuFeO_2のスピン波分散関係における微細構造 (2011)
  • Author(s): 須能梓
  • Organizer: 日本物理学会春季大会
  • Place of Presentation: 新潟大学
  • Year and Date: 2011-03-26
• [Presentation] CuFeO_2のスピン波分散関係における微細構造須能梓 (2011)
  • Author(s): 中島多朗, 満田節生, 寺田典樹, 金子耕士, 山内宏樹, 木村尚次郎
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 新潟大学
  • Year and Date: 2011-03-25
• [Presentation] 三角格子反強磁性体CuFeO_2における磁気基底状態の圧力変化 (2010)
  • Author(s): 寺田典樹, 長壁豊隆、北澤英明
  • Organizer: 日本中性子科学会年会
  • Place of Presentation: 東北大学
  • Year and Date: 2010-12-09
• [Presentation] 共鳴軟X線回折によるCuFe_1-xGaxO_2_(x=0.022)のd-p混成軌道の直接観測 (2010)
  • Author(s): 田中良和, 寺田典樹, 中島多朗, 小島太郎, 高田恭孝, 大浦正樹, 満田節生, 仙波泰徳, 大橋治彦, 辛埴
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 大阪府立大学
  • Year and Date: 2010-09-24
• [Presentation] 共鳴軟X線回折によるCuFe_<1-x>_Ga_x_O_2_(x=0.022)のd-p混成軌道の直接観測 (2010)
  • Author(s): 田中良和
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 大阪府立大学
  • Year and Date: 2010-09-24
• [Presentation] フラストレートした2等辺三角格子反強磁性体CuMnO_2の中性子散乱 (2010)
  • Author(s): 寺田典樹, 北澤英明, 目時直人, 大山研司
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 岡山大学
  • Year and Date: 2010-03-22
• [Presentation] マルチフェロイックCuFeO_2の4-sublattice磁気相に固有な緩和型誘電分散の磁場変化 (2010)
  • Author(s): 山野元義, 長途大輔, 中島多朗, 満田節生, 寺田典樹, 北沢英明, 竹端寛治, 高増正
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 岡山大学
  • Year and Date: 2010-03-22
• [Presentation] マルチフェロイックCuFeO_2の基底状態4-sublattice相における異常分極メモリー効果 (2010)
  • Author(s): 山崎裕恵, 山野元義, 前嶋優一, 中島多朗, 満田節生, 寺田典樹, 北澤英明, 竹端寛治, 高増正
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 岡山大学
  • Year and Date: 2010-03-22
• [Presentation] フラストレートした2等辺三角格子反強磁性体CuMnO_2の中性子散乱 (2010)
  • Author(s): 寺田典樹
  • Organizer: 2010年日本物理学会春季大会
  • Place of Presentation: 岡山大学
  • Year and Date: 2010-03-22
• [Presentation] マルチフェロイックCuFeO_2の4-sublattice 磁気相に固有な緩和型誘電分散の磁場変化 (2010)
  • Author(s): 山野元義
  • Organizer: 2010年日本物理学会春季大会
  • Place of Presentation: 岡山大学
  • Year and Date: 2010-03-22
• [Presentation] マルチフェロイックCuFeO_2の基底状態4-sublattice 相における異常分極メモリー効果 (2010)
  • Author(s): 山崎裕恵
  • Organizer: 2010年日本物理学会春季大会
  • Place of Presentation: 岡山大学
  • Year and Date: 2010-03-22
• [Presentation] 中性子回折による磁場配向過程解析とX線回折による磁場誘起多段階格子変形の観測 (2010)
  • Author(s): 寺田典樹
  • Organizer: 第9回強磁場応用専門研究会
  • Place of Presentation: 東京大学
  • Year and Date: 2010-02-23
• [Presentation] 共鳴X線回折によるCuFeO_2の超格子反射の観測 (2009)
  • Author(s): 寺田典樹, 中島多朗, 満田節生, 田中良和, 北澤英明
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 熊本大学
  • Year and Date: 2009-09-28
• [Presentation] 共鳴X線回折によるCuFeO_2の超格子反射の観測 (2009)
  • Author(s): 寺田典樹
  • Organizer: 2009年日本物理学会秋季大会
  • Place of Presentation: 熊本大学
  • Year and Date: 2009-09-28
• [Presentation] 中性子回折による磁場配向過程解析とX線回折による磁場誘起多段階格子変形の観測 (2009)
  • Author(s): 寺田典樹
  • Organizer: 日本鉄鋼協会フォーラム「相変態に及ぼす磁場効果の解明と磁気エネルギー評価」
  • Place of Presentation: 東京ステーションコンファレンス
  • Year and Date: 2009-06-04
• [Presentation] マルチフェロイックCuFeO_2の4-sublattice磁気相に固有な誘電分散 (2009)
  • Author(s): 山野元義, 栗原一徳, 増田一也, 吉冨啓祐, 中島多朗, 満田節生, 寺田典樹, 北沢英明
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-28
• [Presentation] マルチフェロイックCuFeO_2における分極メモリー効果 (2009)
  • Author(s): 山崎裕恵, 増田一也, 山野元義, 中島多朗, 満田節生, 寺田典樹, 北沢英明, Karel Prokes, Klaus Kifer, Sebastian Kausche
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-28
• [Presentation] 4軸中性子回折と3次元中性子偏極解析を相補的に用いたマルチフェロイックCu(FeGa)O_2の磁気構造解析 (2009)
  • Author(s): 中島多朗, 満田節生, 高橋慶一郎, 吉冨啓祐, 寺田典樹, 北澤英明, 松田雅昌, 加倉井和久, 野田幸男, 木村宏之
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-28
• [Presentation] マルチフェロイックCuFeO2における分極メモリー効果 (2009)
  • Author(s): 山野元義
  • Organizer: 2009年日本物理学会春季大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-28
• [Presentation] マルチフェロイックCuFeO2の4-sublattice磁気相に固有な誘電分散 (2009)
  • Author(s): 山崎裕恵
  • Organizer: 2009年日本物理学会春季大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-28
• [Presentation] 4軸中性子回折と3次元中性子偏極解析を相補的に用いたマルチフェロイックCu(FeGa)O2の磁気構造解析 (2009)
  • Author(s): 中島多朗
  • Organizer: 2009年日本物理学会春季大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-28
• [Presentation] フラストレーション系CuFe_1-yGayO_2の楕円らせん磁気構造と格子変調 (2009)
  • Author(s): 寺田典樹, 中島多朗, 満田節生, 松田雅昌, 加倉井和久, 田中良和, 北澤英明
  • Organizer: 日本物理学会年次大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-27
• [Presentation] フラストレーション系CuFe1-yGayO2の楕円らせん磁気構造と格子変調 (2009)
  • Author(s): 寺田典樹
  • Organizer: 2009年日本物理学会春季大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-27
• [Presentation] X-ray Diffraction Measurements under High Magnetic Fields on Triangular Lattice Antiferromagnet CuFeO_2 (2009)
  • Author(s): N.Terada, Y.Narumi, Y.Sawai, K.Katsumata, U.Staub, Y.Tanaka, A.Kikkawa, T.Fukui, K.Kindo, T.Yamamoto, R.Kanmuri, M.Hagiwara, H.Toyokawa, T.Ishikawa, H.Kitamura
  • Organizer: JAEA Symposium : X-ray and High Magnetic Feild, SPring-8
  • Year and Date: 2009-03-05
• [Presentation] Elliptical proper helical magnetic structure and the lattice modulation in the multiferroic CuFe_1-yGayO_2 (2009)
  • Author(s): N.Terada, T.Nakajima, S.Mitsuda, M.Matsuda, K.Kakurai, Y.Tanaka, H.Kitazawa
  • Organizer: Polarized Neutrons and Synchrotron X-rays for Magnetism (PNSXM 2009) Bonn
  • Place of Presentation: Germany
• [Presentation] Dielectric relaxation in a nonferroelectric phase of magnetoelectric multiferroic CuFeO_2 (2009)
  • Author(s): S.Mitsuda, M.Yamano, K.Kuribara, T.Nakajima, K.Masuda, K.Yoshitomi, N.Terada, H.Kitazawa, K.Takenaka, T.Takamasu
  • Organizer: International Conference on Magnetism (ICM 2009)
  • Place of Presentation: Karlsruhe
• [Presentation] High-field/multi-frequency ESR measurements on the triangular lattice antiferromagnet CuFeO_2 (2009)
  • Author(s): S.Kimura, N.Nishihagi, H.Yamaguchi, T.Kashiwagi, M.Hagiwara, N.Terada, K.Kindo
  • Organizer: Research in High Magnetic Fields (RHMF 2009)
  • Place of Presentation: Dresden
• [Presentation] Elliptical proper helical magnetic structure and the lattice modulation in the multiferroic CuFe_<1-y>Ga_yO_2 (2009)
  • Author(s): 寺田典樹
  • Organizer: Polarized Neutrons and Synchrotron X-rays for Magnetism 2009
  • Place of Presentation: Bonn, Germaby
• [Presentation] Dielectric relaxation in a nonferroelectric phase of magnetoelectric multiferroic CuFeO_2 (2009)
  • Author(s): Setsuo Mitsuda
  • Organizer: International Conference on Magnetism 2009
  • Place of Presentation: Karlsruhe, Germany
• [Presentation] High-field/multi-frequency ESR measurements on the triangular lattice antiferromagnet CuFeO_2 (2009)
  • Author(s): Sojiro Kimura
  • Organizer: Research in High Magnetic Fields 2009
  • Place of Presentation: Dresden, Germany
• [Presentation] 三角格子反強磁性体CuFeO_2の強磁場多周波ESRII (2008)
  • Author(s): 萩原政幸, 西萩尚記, 木村尚次郎, 山口博則, 寺田典樹, 金道浩一
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 岩手大学
  • Year and Date: 2008-09-22
• [Presentation] マルチフェロイックCuFeO_2の非磁性Gaイオン置換による強誘電単相の実現 (2008)
  • Author(s): 寺田典樹, 中島多朗, 満田節生, 北澤英明, 金子耕士, 目時直人
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 岩手大学
  • Year and Date: 2008-09-22
• [Presentation] マルチフェロイックCuFeO2の非磁性Gaイオン置換による強誘電単相の実現 (2008)
  • Author(s): 寺田典樹
  • Organizer: 2008年日本物理学会秋季大会
  • Place of Presentation: 岩手大学
  • Year and Date: 2008-09-22
• [Presentation] Magnetic and dielectric properties in multiferroic CuFe1-yGayO2 (2008)
  • Author(s): Noriki Terada
  • Organizer: Highly Frustrated Magnetism 2008
  • Place of Presentation: Braunschweig
  • Year and Date: 2008-09-10
• [Presentation] Electric polarization memory effect in a magnejoelectric multiferroic cuFe1-xGaxO2 (2008)
  • Author(s): Setsuo Mitsuda
  • Organizer: Polarized Neutrons in Condersed Matter Investimations 2008
  • Place of Presentation: Tokai
  • Year and Date: 2008-09-02
• [Presentation] マルチフェロイック物質CuFe1-yGayO2の磁気誘電特性 (2008)
  • Author(s): 寺田典樹
  • Organizer: 特定領域フラストレーションが創る新しい物性トピカルミーティング
  • Place of Presentation: 京都大学
  • Year and Date: 2008-06-06
• [Presentation] Electric polarization memory effect in a magnetoelectric multiferroic CuFe_1-xGaxO_2 (2008)
  • Author(s): S.Mitsuda, T.Nakajima, M.Yamano, K.Takahashi, H.Yamazaki, K.Masuda, Y.Kaneko, N.Terada, K.Prokes, K.Kiefer
  • Organizer: Polarized Neutrons in Condersed Matter Investigations 2008
  • Place of Presentation: Tokai
• [Presentation] Magnetic and dielectric properties in multiferroic CuFe_1-y GayO_2 (2008)
  • Author(s): N.Terada, T.Nakajima, S.Mitsuda, H.Kitazawa
  • Organizer: Highly Frustrated Magnetism 2008
  • Place of Presentation: Braunschweig
• [Presentation] マルチフェロイック物質CuFe_1-yGayO_2の磁気誘電特性 (2008)
  • Author(s): 寺田典樹、中島多朗、満田節生、北澤英明、金子耕士、目時直人
  • Organizer: 特定領域フラストレーションが創る新しい物性トピカルミーティング「フラストレーションとマルチフェロイクス」
  • Place of Presentation: 京大宇治キャンパス
• [Remarks] ホームページ等
  • URL: http://www.nims.go.jp/nsg/terada/index.html
• [Remarks]
  • URL: http://www.nims.go.jp/nsg
• [Remarks]
  • URL: http://www.nims.go.jp/nsg/index.html
• [Remarks]
  • URL: http://www.nims.go.jp/nsg/index.html