XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)最新文献

{"title":"Thermal conductivity of solid solutions (Bi/sub y/Sb/sub 1-y/)/sub 2/Te/sub 3/ for y=0.7-0.8 grown by method of zone melting","authors":"A. I. Anukhin","doi":"10.1109/ICT.1997.667053","DOIUrl":"https://doi.org/10.1109/ICT.1997.667053","url":null,"abstract":"The linear deviation of concentration of excessive tellurium in the melt during zone melting C=C/sub o/(I+X/l), where C/sub o/ is the starting concentration of tellurium in the load, X is the zone co-ordinate on the ingot, and l is the length of the melting zone, is used for investigating the dependency of thermoelectric qualities of solid solutions (Bi/sub y/Sb/sub 1-y/)/sub 2/Te/sub 3/ on chemical composition distributed along the ingot. According to the distributed thermoelectric parameters obtained in the temperature range 150-360 K, the general projection of solidus line was made, depicting tellurium for solid solutions (Bi/sub y/Sb/sub 1-y/)/sub 2/Te/sub 3/ around the chemical composition with the melting temperature close to maximum. There exists a dependency of distribution of the thermoelectric parameters of the solid solutions along the ingot on the surface shape of their solidus. The distribution of remaining thermal conductivity, obtained as a result of subtraction of electron component, calculated on the basis of the Wiedemann Franz law, from the general one, calculated from the Seebeck coefficient figure of merit and electrical conductivity, depends on the ratio of atom parts of bismuth and antimony as well as on excessive concentration of tellurium in the melt. For y>0.5 around room temperature, the remaining thermal conductivity is an abrupt maximum corresponding to the area of intrinsic conductivity of the ingot The maximum of remaining thermal conductivity under y=0.7-0.8 and T=300K reaches the figure of 6.0/spl times/10/sup -2/ W/K/cm when at the same time the contribution of ambipole component of conductivity, according to the calculations, under this temperature is not above 6.0/spl times/10/sup -3/ W/K/cm. The most suitable mechanism, which can explain the anomalous increase of thermal conductivity in the solid solutions with chemical composition corresponding to the area where the solidus overlaps with stoichiometric cut, is transport of heat by excitons.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"05 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128304560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of p-type PbEuTe/PbTe MQW structures with high thermoelectric figures of merit in the PbTe quantum wells","authors":"T. Harman, D. Spears, D. Calawa, S. Groves, M. P. Walsh","doi":"10.1109/ICT.1997.667169","DOIUrl":"https://doi.org/10.1109/ICT.1997.667169","url":null,"abstract":"A large enhancement in the Seebeck coefficient, thermoelectric power factor and figure of merit (Z/sub 2D/T) is reported in very high carrier concentration p-type PbTe quantum wells grown by molecular beam epitaxy. The estimated Z/sub 2D/T (using accepted bulk values for lattice thermal conductivity) is as high as 1.5 at 300 K. Power factor values up to 160 /sub /spl mu//Wcm/sup -1/K/sup -2/ were measured at 300 K, indicating a power factor in p-type quantum wells that is approximately five times the best bulk or homogeneous p-type value. Thinner barriers yielded lower thermoelectric power factors and figures of merit. The high power factor was achieved with a barrier thickness less than half that previously used to demonstrate enhanced thermoelectric power factors in n-type quantum wells. X-ray diffraction/reflection characterization results of the multiple-quantum-well (MQW) structures at both low and high Bragg angles yield precise values for the MQW periodicity.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129443490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the consolidation technique on the thermoelectric properties of mechanically alloyed Bi-Sb","authors":"R. Martin-Lopez, A. Dauscher, X. Devaux, B. Lenoir, H. Scherrer, M. Zandona","doi":"10.1109/ICT.1997.667072","DOIUrl":"https://doi.org/10.1109/ICT.1997.667072","url":null,"abstract":"The aim of this work is multiple: first the synthesis by mechanical alloying of homogeneous Bi/sub 85/Sb/sub 15/ polycrystalline powder alloys, that have been achieved with an adequate ball to powder weight ratio (10:1), second the consolidation of the powders either by sintering or by hot extrusion in order to try to introduce a texture in the material and finally to measure the thermoelectric properties of the consolidated samples in the 77-300 K temperature range.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"126 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129754841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of FGM thermoelectric materials in Japan-the state of the art","authors":"I. Shiota, I. Nishida","doi":"10.1109/ICT.1997.667154","DOIUrl":"https://doi.org/10.1109/ICT.1997.667154","url":null,"abstract":"Two times higher performance than a traditional thermoelectric material can be expected if the proper carrier concentration gradient is tailored to fit the temperature gradient. Performing a stepwise change of carrier concentration is also a method for practical application. That is a fundamental concept of energy converting functionally graded materials (FGM). It is essential to choose a proper material for each part to fit the temperature gradient. The proper material is a material with the proper carrier concentration and a proper compound to match the temperature of each part along the temperature gradient. Joining of these FGM materials and fitting electrodes with FGM interfaces are also core techniques, because thermal stress relaxation caused by the difference of thermal expansion coefficients is important at a high temperature. Joining two Bi/sub 2/Te/sub 3/ samples with carrier concentrations n/sub c/ of 1.0 and 4.5/spl times/10/sup 25/ was done by the ordinal soldering technique or diffusion bonding. The specific temperature range of the Seebeck coefficient /spl alpha/ for the joined Bi/sub 2/Te/sub 3/ is extended from 50 to 100 K, and the value of /spl alpha/ at the valley between the two materials with different n/sub c/ was higher than both materials. The sintered n-type PbTe FGM with 3 layers of n/sub c/=3.51, 2.60 and 2.26/spl times/10/sup 25/ was prepared by hot pressing. The effective maximum power P/sub max/ of the FGM at the temperature difference of /spl Delta/T=310 K is 150 Wm/m/sup 2/ and is about 7% larger than that of the layer with n/sub c/=3.51/spl times/10/sup 25/ whose P/sub max/ is the greatest in all layers.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129238661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-temperature oxidation behavior of PbTe and oxidation-resistive glass coating","authors":"Lidong Chen, T. Goto, R. Tu, T. Hirai","doi":"10.1109/ICT.1997.667101","DOIUrl":"https://doi.org/10.1109/ICT.1997.667101","url":null,"abstract":"Oxidation of lead telluride (PbTe) is a serious issue for thermoelectric applications. In the present study, the oxidation behavior of PbTe was studied at oxygen partial pressures of 10 Pa to 0.1 MPa in the temperature range between 700 and 900 K. At moderately low oxygen partial pressures and high temperatures, mass loss was observed and the oxide layers (Pb/sub 3/TeO/sub 5/ or Pb/sub 5/TeO/sub 7/) formed on the PbTe surface. At high oxygen partial pressures and low temperatures, mass gain was observed and PbTeO/sub 3/ or Pb/sub 2/TeO/sub 4//PbTeO/sub 3/ oxide layers formed on the PbTe surface. When the temperature was higher than 819 K, PbTeO/sub 3/ melted and dropped down from the specimen. Oxidation-resistive glasses were coated on the PbTe surface. The glass-coated PbTe showed excellent oxidation resistance showing no mass change at 773 K.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127926135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhenium silicide thin films: structural analysis of the ReSi/sub 2-/spl delta//-phase","authors":"W. Pitschke, A. Heinrich, J. Schumann","doi":"10.1109/ICT.1997.667135","DOIUrl":"https://doi.org/10.1109/ICT.1997.667135","url":null,"abstract":"The structure of the semiconducting ReSi/sub 2-/spl delta// phase formed in binary rhenium silicide thin films has been studied using X-ray powder diffraction. The films were deposited by magnetron cosputtering onto unheated, oxidized Si-wafers. Subsequent annealing results in crystallization of the amorphous films. By means of Rietveld analysis the unit cell dimensions and the atomic occupation factors of the crystalline phases have been determined. After annealing the film at T=973 K a ReSi/sub 2-/spl delta//-phase phase was formed the chemical composition of which has been determined to be ReSi/sub 1.55/. Temperature enhancement gave rise to increase the occupation factors of Si resulting in an chemical composition of ReSi/sub 1.78/ at T=1073 K. This phase crystallizes with primitive space group P1 and a=0.3138 nm, b=0.3118 nm, c=0.7688 nm and /spl alpha/=89.83.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127991327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoelectric properties of magnesium silicide processed by powdered elements plasma activated sintering method","authors":"T. Kajikawa, K. Shida, S. Sugihara, M. Ohmori, T. Hirai","doi":"10.1109/ICT.1997.667125","DOIUrl":"https://doi.org/10.1109/ICT.1997.667125","url":null,"abstract":"Efficient, inexpensive and non-toxic thermoelectric elements such as silicides should be developed for large scale application such as recovering the combustion heat of municipal solid waste, of which the characteristics are greatly fitted to thermoelectric power generation. This paper introduces the characterization and thermoelectric properties of undoped and doped n-type magnesium silicide processed by the powdered elements spark plasma sintering method. The patterns by powder X-ray diffractometry showed that it had typical polycrystalline phase. The temperature dependence of thermoelectric properties such as the Seebeck coefficient and electrical conductivity were measured for the temperature range from 300 K to 773 K. As a result, a power factor value 6.0/spl times/10/sup -4/ (W/mK/sup 2/) was obtained at 773 K for a doped sample.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134230784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoelectric properties of the Skutterudite-related phase CoSn/sub 1.5/Te/sub 1.5/","authors":"Y. Nagamoto, K. Tanaka, T. Koyanagi","doi":"10.1109/ICT.1997.667146","DOIUrl":"https://doi.org/10.1109/ICT.1997.667146","url":null,"abstract":"A new skutterudite-related phase CoSn/sub 1.5/Te/sub 1.5/ was prepared. This new phase is one of a large family of skutterudites which have shown a good potential for thermoelectric applications. Polycrystalline samples were prepared by the spark plasma sintering method and were characterized by x-ray diffractometry. CoSn/sub 1.5/Te/sub 1.5/ has a cubic lattice, space group Im3. With a=9.121 /spl Aring/. The electrical conductivity, the Seebeck coefficient, and the thermal conductivity were measured over the temperature range 300-900 K. The temperature dependence of the electrical conductivity revealed that CoSn/sub 1.5/Te/sub 1.5/ was a semiconductor with a band gap of 0.7 eV. The electrical conductivity increased by doping with Ni. Large Seebeck coefficients up to -450 /spl mu/V/K were obtained on the n-type undoped samples. The thermal conductivity of CoSn/sub 1.5/Te/sub 1.5/ was substantially lower than that of the binary isostructural compounds CoSb/sub 3/ and IrSb/sub 3/. The potential of this material for thermoelectric applications is discussed.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133524435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoelectric coolers with vortex apparatus","authors":"G.A. Smolyar","doi":"10.1109/ICT.1997.667625","DOIUrl":"https://doi.org/10.1109/ICT.1997.667625","url":null,"abstract":"Results of thermodynamic characteristics of the combined cooling system consisting of a thermoelectric cooler and a jet cooler in the form of a vortex tube have been given. General relations for their description based on the exergetic method of thermodynamic system calculations have been obtained. Results supporting such devices efficiency have been presented. Experimental results of such system variations study have been given. Possibilities of their use in flying vehicles for electronic equipment cooling have been considered.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133645219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive research of the Institute of Thermoelectricity, Ukraine on the theory, material science and applications of thermoelectricity","authors":"L. Anatychuk","doi":"10.1109/ICT.1997.667605","DOIUrl":"https://doi.org/10.1109/ICT.1997.667605","url":null,"abstract":"Results of works on the phenomenological and microscopic theory of thermoelectricity together with the theory of thermoelectric energy conversion have been presented. New thermoelectric effects, generalizations of the basic Thomson relations, generalizations of the electric current induction phenomena for the case of a thermoelectric medium, generalizations in thermoelements description as well as methods for new types of thermoelements discovery have been examined.","PeriodicalId":174813,"journal":{"name":"XVI ICT '97. Proceedings ICT'97. 16th International Conference on Thermoelectrics (Cat. No.97TH8291)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117341647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}