Development of thermoelectric devices based on strongly correlated cobalt compounds

基于强相关钴化合物的热电器件的开发

基本信息

批准号：
14205095
负责人：
KAJITANI Tsuyoshi
金额：
$ 29.7万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

□Thermoelectric thin layered samples ;By means of the pulsed laser deposition (PLD) technique, which was realized by the financial aid from JSPS under the present contract, following research results were obtained.1. Smooth and well oriented La_<0.7>Ca_<0.3>MnO_3, La_<0.4>Sr_<0.6>CoO_3 and SrTiO_3 thin films with the thickness in the range from 5nm to 100nm were successfully grown by the PLD method.2. Very smooth, e.g., the RMS of the surface roughness was about 0.5nm, thin oxide films were grown by PLD method at the optimized environment gas pressure and substrate temperature.3. Flat and smooth La_<0.7>Ca_<0.3>MnO_3/La_<0.4>Sr_<0.6>CoO_3 multi-layer sample was grown by the PLD method and Shottky barrier height between two layers was measured. The barrier height was 0.6V, being too high for the thermionic devices.□Following results were obtained for bulk samples ;1. Many thin plate single crystals of Ca349 were grown by the flux-growth method. Grown single crystals have electrically co … More nducting c-planes parallel to the flat surfaces. These thin plates were carefully aligned parallel to the graphite die bottom and sintered by the spark plasma sintering (SPS) machine controlled at about 900 Celsius degree under the pressure at about 20MPa. Obtained block exhibit high thermoelectric property, i.e., ZT=0.4 at 1000K.2. Nearly isomorphic thermoelectric bismuth-rhodium and -cobalt oxides were elucidated. Following results have been obtained. Chemical properties of both systems are quite similar.(1)Crystal structure of thermoelectric Bi-(Sr,Ba)-Rh-O was studied by EPMA and TEM. Four or five dimensional structure model was obtained from the determined chemical contents and HREM images.(2)Crystal structure of thermoelectric Bi-(Sr,Ca)-Rh-O was studied by EPMA and TEM. Four or five dimensional structure model was obtained from the determined chemical contents and HREM images.(3)Thermoelectric properties of Ba, Sr or Ca substituted γ-Na_<0.7>CoO_2 samples, which were synthesized by the ion-exchange technique, were studied and their crystal structures were determined by TEM and X-ray diffraction measurement. Most of the crystals were incommensurated CDW phases. Less

□热电薄层样品；采用本合同JSPS资助实现的脉冲激光沉积（PLD）技术，取得了以下研究成果： 1． 0.3>MnO_3、La_<0.4>Sr_<0.6>CoO_3、SrTiO_3薄膜，厚度范围为5nm～通过PLD方法成功生长了100nm。2．非常光滑，即表面粗糙度的RMS约为0.5nm，在优化的环境气压和衬底温度下，通过PLD方法生长了薄氧化膜。3．采用PLD方法生长La_<0.7>Ca_<0.3>MnO_3/La_<0.4>Sr_<0.6>CoO_3多层样品并测量了两层之间的肖特基势垒高度为0.6V，对于热电子器件来说太高了。对于大块样品，获得了以下结果： 1．通过助熔剂生长法生长了许多薄板Ca349单晶。单晶具有平行于平坦表面的导电 c 面，这些薄板被小心地平行于石墨模具底部对齐，并通过放电等离子烧结进行烧结。 (SPS)机在约20MPa的压力下控制在约900摄氏度，得到的块体表现出较高的热电性能，即在1000K时ZT=0.4。2 阐明了接近同构的热电铋铑和钴氧化物。 (1)热电晶体结构。通过EPMA和TEM对Bi-(Sr,Ba)-Rh-O进行了研究，根据测定的化学含量和HREM图像得到了四维或五维结构模型。(2)热电Bi-(Sr,Ca)-的晶体结构。通过EPMA和TEM对Rh-O进行了研究，根据测定的化学含量和HREM图像得到了四维或五维结构模型。(3)Ba、Sr或Ca取代的热电性能。对采用离子交换技术合成的γ-Na_<0.7>CoO_2样品进行了研究，并通过TEM和X射线衍射测量确定了其晶体结构，大部分晶体为不可计量的CDW相。

项目成果

期刊论文数量（206）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Jahn-Teller distortion and cluster-glass like behavior in La_<0.875>Ca_<0.125>MnO_3

La_<0.875>Ca_<0.125>MnO_3 中的 Jahn-Teller 畸变和类簇玻璃行为

DOI：
发表时间：
2002
期刊：
J.Phys.Chem.Solids 63
影响因子：
0
作者：
D.Kaneko;S.Begum
通讯作者：
S.Begum

Fabrication and Performance of an Oxide Thermoelectric Power Generator

氧化物热电发电机的制造和性能

DOI：
发表时间：
2002
期刊：
Proceedings of the 21st International Conference on Thermoelectrics (ITC 2002)
影响因子：
0
作者：
西原直枝;西川雅弥;小林弘造;北村規明;田辺新一;H.-J.Kwon;Y.Ono
通讯作者：
Y.Ono

S.Begum他: "Low-energy excitation in La_<1-x>Ca_xMuO_3 single Crystals with 0.05【less than or equal】x【less than or equal】0.20"Applied Physics. A74. S625-S627 (2002)

S. Begum等人：“0.05【小于或等于】x【小于或等于】0.20的La_<1-x>Ca_xMuO_3单晶中的低能激发”S625-S627（2002）。