DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Lee, Soon-Chil | - |
dc.contributor.advisor | 이순칠 | - |
dc.contributor.author | Yoon, Dong-Young | - |
dc.contributor.author | 윤동영 | - |
dc.date.accessioned | 2011-12-14T07:29:03Z | - |
dc.date.available | 2011-12-14T07:29:03Z | - |
dc.date.issued | 2011 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=466339&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/47669 | - |
dc.description | 학위논문(박사) - 한국과학기술원 : 물리학과, 2011.2, [ vii, 105 p. ] | - |
dc.description.abstract | The canting angles and fluctuation of the magnetic ion spins of spinel oxide $MnCr{_2}O4}$ were studied by nuclear magnetic resonance (NMR) at low temperatures, which has a collinear ferrimagnetic order below $T_C$ and a ferrimagnetic spiral order below $T_s < T_C$. Contrary to previous reports, only one spin canting angle of Cr ions was observed. The spin canting angles of Mn and Cr ions in the ferrimagnetic spiral obtained at a liquid-He temperature were $43\^{\circ}$ and $110\^circ$, respectively. The nuclear spin-spin relaxation was determined by the Suhl-Nakamura interaction at low temperatures but the relaxation rate $T_2^{-1}$ increases rapidly as the temperature approaches $T_s$. This indicates that the fluctuation of the spiral component becomes faster as the temperature increases but not fast enough to leave an averaged hyperfine field to nuclei in the time scale of nuclear spin precession in the ferrimagnetic phase, which is on the order of $10^{-8}$ s. The spiral volume fraction measured for various temperatures reveals that the collinear and the spiral ferrimagnetic phases are mixed below the transition temperature of the spiral order. The temperature hysteresis in the volume fraction implies that this transition has first-order characteristics. | eng |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | Ferrimagnetic spiral | - |
dc.subject | NMR | - |
dc.subject | MnCr2O4 | - |
dc.subject | Multiferroic | - |
dc.subject | spin fluctuation | - |
dc.subject | 스핀 요동 | - |
dc.subject | 준강자성 나선구조 | - |
dc.subject | 핵자기공명 | - |
dc.subject | MnCr2O4 | - |
dc.subject | 다강성체 | - |
dc.title | Spin structure and fluctuation of spinel oxide $\mathrm{MnCr_2O_4}$ investigated by NMR | - |
dc.title.alternative | 스피넬 산화물 $\mathrm{MnCr_2O_4}$ 의 스핀 구조 및 요동에 관한 핵자기공명 연구 | - |
dc.type | Thesis(Ph.D) | - |
dc.identifier.CNRN | 466339/325007 | - |
dc.description.department | 한국과학기술원 : 물리학과, | - |
dc.identifier.uid | 020055104 | - |
dc.contributor.localauthor | Yoon, Dong-Young | - |
dc.contributor.localauthor | 윤동영 | - |
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