新奇なマルチフェロイック酸化物の時間分解分光

2008 年度 研究成果報告書

• 研究課題/領域番号: 19840026
• 研究種目: 若手研究(スタートアップ)
• 配分区分: 補助金
• 研究分野: 物性Ⅰ
• 研究機関: 京都大学
• 研究代表者: K・R MAVANI 京都大学, 物質-細胞統合システム拠点, 特定研究員(WPI) (10452260)
• 研究期間 (年度): 2007 – 2008
• キーワード: 強相関電子系 / マルチフェロイック / テラヘルツ分光 / ラマン分光

研究概要

We synthesized different exotic oxide thin film and polycrystalline pellets. We observed electromagnons in CoCr_2O_4 thin film using terahertz time-domain spectroscopy, which is the first such observation for spinel multiferroic. Raman spectroscopy shows transit phonon mode on CoCr_2O_4. Photoinduced effect has been observed in a manganite thin film using visible pump terahertz probe spectroscopy.

研究成果

• [雑誌論文] Effects of disorder and scaling of optical conductivity in Nd_<0.5>Ca_<0.5-x>Ba_xMnO_3(x=0 and 0.02) thin films as observed by terahertz time domain spectroscopy (2008)
  • 著者名/発表者名: K. R. Mavani, M. Nagai, D. S. Rana, H. Yada, I. Kawayama, M. Tonouchi and K. Tanaka
  • 雑誌名: Applied Physics Letters 93 ページ: 231908
• [学会発表] Ultra-Fast Photoinduced Effects on the Charge-Dynamics of Pr_<0.5>Sr_<0.5>MnO_3 Manganite (2009)
  • 著者名/発表者名: K. R. Mavani, D. S. Rana, M. Nagai, M. Tonouchi, K. Tanaka
  • 学会等名: Japanese Physical Society Metting at Rikkyou University
  • 発表場所: Japan
  • 年月日: 20090327-30
• [学会発表] Large Magnetodielectric Effect Observed In Multiferroic CoCr2O_4 Thin Film Using Terahertz Time-Domain Spectroscopy (2009)
  • 著者名/発表者名: K. R. Mavani, M. Nagai, D. S. Rana, M. Tonouchi, K. Tanaka
  • 学会等名: International Workshop on Optical Terahertz Science and Technology, Santa Barbara
  • 発表場所: United States
  • 年月日: 20090307-11
• [学会発表] Poster presentation : "Influence of ferromagnetic ordering and relaxation dynamics in CoCr_2O_4 multiferroic thin film as studied by terahertz time-domain spectroscopy (2008)
  • 著者名/発表者名: K. R. Mavani, M. Nagai, D. S. Rana, M. Tonouchi, K. Tanaka
  • 学会等名: Japanese Physical Society meeting at Iwate University
  • 発表場所: Japan, during
  • 年月日: 20080920-23
• [学会発表] Oral Presentation : "Large drop in dielectric constant at ferromagnetic transition in CoCr_2O_4 thin film as studied by terahertz time-domain spectroscopy (2008)
  • 著者名/発表者名: K. R. Mavani, M. Nagai, D. S. Rana, M. Tonouchi, K. Tanaka
  • 学会等名: The 8^<th> International conference on excitonic processes in condensed matter (EXCON'08) at Kyoto University
  • 発表場所: Japan, during
  • 年月日: 20080622-27
• [学会発表] Oral Presentation : "Scaling of optical conductivity and disorder effect in half-doped manganites Nd_<0.5>Ca_<0.5>Mn_O_3 and Nd_<0.5>Ca_<0.48>Ba_<0.02>MnO_3 thin films as probed by Terahertz time-domain spectroscopy (2008)
  • 著者名/発表者名: K. R. Mavani, M. Nagai, D. S. Rana, H. Yada, I. Kawayama, M. Tonouchi and K. Tanaka
  • 学会等名: American Physical Society meeting (APS, Spring meeting 2008) at New Orleans
  • 発表場所: USA during
  • 年月日: 20080309-14
• [学会発表] Poster presentation : "Large drop in dielectric constant at ferromagnetic transition in CoCr_2O_4 thin film as studied by terahertz time-domain spectroscopy (2008)
  • 著者名/発表者名: K. R. Mavani, M. Nagai, M. Shirai, K. Tanaka, D. S. Rana, I. Kawayama, M. Tonouchi
  • 学会等名: American Physical Society meeting (APS, Spring meeting 2008) at New Orleans
  • 発表場所: USA during
  • 年月日: 20080309-14