서지주요정보
이중 페롭스카이트 구조를 가지는 $Sr_2FeMoO_6$의 초거대자기저항거동에 관한 연구 = A study on colossal magnetoresistance in double-ordered perovskite $Sr_2FeMoO_6$
서명 / 저자 이중 페롭스카이트 구조를 가지는 $Sr_2FeMoO_6$의 초거대자기저항거동에 관한 연구 = A study on colossal magnetoresistance in double-ordered perovskite $Sr_2FeMoO_6$ / 장원위.
발행사항 [대전 : 한국과학기술원, 2000].
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소장정보

등록번호

8011087

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 00037

휴대폰 전송

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리뷰정보

초록정보

Colossal magnetoresistance - a huge decrease in resistance in response to a magnetic field - has recently been observed in manganese oxides with perovskite structure. This effect is attracting considerable interest from both fundamental and practical points of view. In the context of using this effect in practical devices, a noteworthy feature of these materials is the high degree of spin polarization of the charge carriers, caused by half metallic nature of these materials. In principle, this allows spin dependent carrier scattering processes, and hence the resistance to be strongly influenced by low magnetic fields. This field control has been demonstrated for low-field intergrain magnetoresistance(MR) low-field intergrain magnetoresistance(MR) at room temperature has been reported for sintered polycrystalline samples of $Sr_2FeMoO_6$(SFMO). This compound has a structure with a NaCl-type ordering of B sites cations in cubic $ABO_3$ perovskite and this compound are expected to be highly spin polarized even at room temperature. This feature makes SFMO a most prospective candidate for magnetic sensors in a form of tunnel junction devices. In this study, We have studied SFMO compound that has been not known until now. The phase formation condition, magnetization and M-H curves of bulk SFMO fabricated by standard solid-state reaction was investigated. Also the magnetoresistance of bulk SFMO was measured in order to confirm colossal magnetoresistance effect. Double-ordered perovskite SFMO with a single phase was formed at such sintering condition as 5%$H_2$/Ar reductive ambients, 1200℃, and 3hrs. Bulk SFMO has the high ferromagnetic transition temperature(TC∼420K) and has ferromagnetic characteristics from 8K to room temperature and has about 8% magnetoresistance(MR). Because SFMO thin films were deposited using sputtering method for commercial application, amorphous SFMO thin films were deposited on LAO, STO substrate using bulk SFMO target and then SFMO thin films were obtained by annealing at 5%$H_2$/Ar reductive ambients. We measured the M-H curve and magnetores istance of SFMO thin films. SFMO thin films show weaker ferromagnetic characteristics than bulk SFMO. Also, SFMO thin films have very low magnetoresis tance at low temperature and increasing temperature, SFMO thin films have not colossal magnetoresistance. We think this reason is that SFMO thin films have not dense thin films and have a second phase.

서지기타정보

서지기타정보
청구기호 {MMS 00037
형태사항 iv, 97 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Weon-Wi Jang
지도교수의 한글표기 : 이원종
지도교수의 영문표기 : Won-Jong Lee
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 96-97
주제 페롭스카이트
스핀 터널링
페리강자상
초거대자기저항
Perovkite
Spin polarized tunneling
Ferrimagnetism
Colossal magnetoresistance(CMR)
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