http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Thermoelectric Properties of the Hot - Pressed Bi2(Te0.85Se0.15)3 Alloy with Addition of BN Powders
Hyun, Dow Bin,Oh, Tae Sung,Lee, Sun Kyung,Lee, Jun Soo 대한금속재료학회(대한금속학회) 2000 METALS AND MATERIALS International Vol.6 No.6
Thermoelectric properties of the hot-pressed Bi₂(Te_(0.85)Se_(0.15)₃ alloy were investigated with the addition of BN powders as phonon scattering centers. The Seebeck coefficient and electrical resistivity of the alloy increased as the volume fraction of BN increased. Although the thermal conductivity of the alloy decreased as the volume fraction of BN increased due to the reduction of κ_(el), the lattice thermal conductivity varied little. The figure-of-merit of the alloys, 1.6×10^(-3)/K without the addition of BN, decreased as the volume fraction of BN increased because the increment of the electrical resistivity was much larger than the decrement of the thermal conductivity due to grain refinement.
BN 을 산란센터로 첨가한 (Bi0.2Sb0.8)2Te3 가압소결체의 열전특성
현도빈,오태성,이준수,김항종 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.9
Thermoelectric properties of the polycrystalline (Bi_(0.2)Sb_(0.8))₂Te₃, fabricated by mechanical alloying and hot-pressing, were investigated with addition of BN as scattering centers. The Seebeck coefficient of the hot-pressed (Bi_(0.2)Sb_(0.8))₂Te₃ was not affected by addition of BN. The thermal conductivity of the hot-pressed (Bi_(0.2)Sb_(0.8))₂Te₃ decreased with increasing the volume fraction of BN due to the reduction of k_(el) However, the lattice thermal conductivity k_(ph) was little varied with addition of BN. The figure-of-merit of the hot-pressed (Bi_(0.2)Sb_(0.8))₂Te₃ was 3.05×10^(-3)/K without addition of BN and was lowered with increasing the volume fraction of BN, because the increase of the electrical resistivity was larger than the reduction of the thermal conductivity due to the grain refinement.
가압소결법으로 제조된 p형 Bi2Te3-Sb2-Te3-Sb2Se3 의 삼원계 합금의 열전특성
현도빈,오태성,이준수,김항종 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.5
P-type 20% Bi₂Te₃-(80-x)% Sb₂Te₃-x% Sb₂Se₃ (0≤x≤7) alloy powders, fabricated by mechanical alloying and melting/grinding processes, were hot pressed and their thermoelectric properties were characterized with the Sb₂Se₃ content and the powder processing method. The Seebeck coefficient and electrical resistivity of the hot-pressed 20% Bi₂Te₃-(80-x)% Sb₂Te₃-x% Sb₂Se₃ alloys increased with increasing the Sb₂Se₃ content due to the reduction of the hole concentration. Although the total thermal conductivity of the hot-pressed 20% Bi₂Te₃-(80-x)% Sb₂Te₃-x% Sb₂Se₃ alloys decreased with increasing the Sb₂Se₃ content due to the reduction of κ_(el), the lattice thermal conductivity κ_(ph) was not lowered. The figure-of-merit of the hot-pressed 20% Bi₂Te₃-(80-x)% Sb₂Te₃-x% Sb₂Se₃ alloys decreased with increasing the Sb₂Se₃ content, because the increment of the electrical resistivity was much larger than the decrement of the thermal conductivity and the increment of the Seebeck coefficient.
Zone melting 법으로 성장시킨 90 % Bi2Te3-10 % Bi2Se3 n 형 단결정에서 길이방향에 따른 열전특성의 변화
현도빈,하헌필 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.3
CdI₂ and CdCl₂ doped n-type 90% Bi₂Te₃ 10% Bi₂Se₃ single crystals were grown by the vertical zone melting method, and the thermoelectric properties along the ingot were analyzed. The sharp increase of the Seebeck coefficient and electrical resistivity at the last-to-freeze region were considered as a result of the evaporation of I and Cl from the molten zone. The maximum Figure-of-Merit of the CdI₂ and CdCl₂ doped n-type 90% Bi₂Te₃ 10% Bi₂Se₃ single crystals were 2.7×10^(-3)/K and 2.8×10^(-3)/K, respectively. The higher Figure-of-Merit for the CdCl₂ doped specimens was mainly due to the lower (κ-κ_(el)). The optimum doping amount of CdI₂ and CdCl₂ for n-type 90% Bi₂Te₃-10% Bi₂Se₃ single crystals, grown by the vertical zone melting method, were 0.075-0.10 wt% and 0.04-0.05 wt%, respectively.
기계적 합금화 공정으로 제조한 n 형 PbTe 가압소결체의 소결특성과 열전특성
현도빈,오태성,최재식 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.4
Bi-doped n-type PbTe thermoelectric materials were fabricated by mechanical alloying and hat pressing, and the sintering characteristics and thermoelectric properties of the hot-pressed PbTe were characterized. Even without Bi doping, the hot-pressed PbTe exhibited a negative Seebeck coefficient and thus n-type conduction. With increasing the hot pressing temperature from 650℃ to 800℃, the temperature at which a maximum figure-of-merit was obtained shifted to higher temperature. When hot pressed at 650℃, 0.3 wt% Bi-doped PbTe exhibited a maximum figure-of-merit of 1.33×10³/K at 200℃ With hot pressing at 750℃ and 800℃, 0.1 wt% Bi-doped PbTe exhibited maximum figure-of-merits of 1.27×10^(-3)/K at 250℃ and 1.3×10^(-3)/K at 400℃ respectively.
현도빈,남승의,오태성,최재식 대한금속재료학회(대한금속학회) 1995 대한금속·재료학회지 Vol.33 No.7
Mechanical alloying behavior of Bi₂Te₃ alloy, which is the basic composition of thermoelectric materials used for thermoelectric cooling applications, has been investigated with variations of milling time and ball-to-powder weight ratio. Formation of Bi₂Te₃ intermetallic compound was completed by mechanical alloying of elemental Bi and Te powders for 1 hour at ball-to-powder weight ratio of 2 : 1 Processing time for completion of Bi₂Te₃ formation was found to be inversely proportional to the ball-to-powder weight ratio. Formation of Bi₂Te₃ was completed by mechanical alloying for 30 minutes and 10 minutes at ball-to-powder weight ratio of 4:1 and 10:1, respectively. Lattice constants of Bi₂Te₃ processed by mechanical alloying, a=0.4387㎚ and c=3.0481㎚, were not varied with ball-to-powder weight ratio and milling time. Lattice parameters of mechanically alloyed Bi₂Te₃ are in excellent agreement with values of a=0.4385㎚ and c=3.0483㎚, which were reported for Bi₂Te₃ powders processed by melting and grinding.
SbI3 및 과잉 Te 첨기에 따른 n 형 (Bi2Te3)0.9(Sb2Te3)0.05(Sb2Se3)0.05 가압소결체의 열전특성
현도빈,오태성,이준수,황창원 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.5
Thermoelectric properties of the n-type (Bi₂Te₃)_(0.9)(Sb₂Te₃)_(0.05)(Sb₂Se₃)_(0.05) alloy prepared by melting/grinding and hot pressing, were investigated with variation of the doping amount of SbI₃and excess Te. With increasing the doping amount of SbI₃ and excess Te, the Seebeck coefficient and electrical resistivity of the hot-pressed (Bi₂Te₃)_(0.9)(Sb₂Te₃)_(0.05)(Sb₂Te₃)_(0.05) alloy were lowered due to the increase in the electron concentration. When SbI₃ and excess Te were doped within 0.1 wt%, SbI₃ exhibited doping effect, i.e., increase in the electron concentration, 2.8 times larger than that of excess Te. The hot-pressed (Bi₂Te3)_(0.9)(Sb₂Te3)_(0.05)(Sb₂Se₃)_(0.05) alloy exhibited maximum figure-of-merits of 2.02×10^(-3)/K and 2.22×10^(-3)/K with doping of 0.025 wt% SbI₃ and 0.2 wt% excess Te, respectively.
P 형 (Bi1-xSbx)2 Te3 열전재료의 기계적 합금화 공정화 열전특성
현도빈,오태성,김항종,정부양 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.3
Thermoelectric properties of p-type polycrystalline (Bi_(1-x)Sb_x)₂Te₃ (0.75 ≤ x ≤ 0.85), fabricated by mechanical alloying and hot pressing, were investigated as a function of the Sb₂Te₃ content and the amount of excess Te addition. The effect of a reduction treatment in Hz atmosphere on thermoelectric properties of (Bi_(1-x)Sb_x)₂Te₃ was also studied. Among (Bi_(1-x)Sb_x)₂Te₃ fabricated by mechanical alloying. (Bi_(0.2)Sb_(0.8))₂Te₃ exhibited the highest figure-of-merit of 2.98×10³/K. When (Bi_(1-x)Sb_x)₂Te₃ powders were reduction-treated in H₂ atmosphere, the Seebeck coefficient and electrical resistivity decreased due to the removal of the oxide layer on the powder surface. With the reduction treatment, the figure-of-merits of (Bi_(0.25)Sb_(0.75))₂Te₃ (Bi_(0.2)Sb_(0.8))₂Te₃, (Bi_(0.15)Sb_(0.85))₂Te₃ were changed from 2.76×10^(-3)/K to 2.79×10^(-3)/K, from 2.98×10^(-3)/K to 2.80×10^-3/K, and from 2.78×10^(-3)/K to 1.81×10^(-3)/K, respectively. When 1.0 wt% excess Te-doped (Bi_(0.2)Sb_(0.8))₂Te₃ powders were reduction-treated, a Figure-of-merit of 3.33×10^(-3)/K was obtained.
과잉 Te 첨가와 성장속도가 22.5% Bi2Te3-77% Sb2Te3 단결정성의 열전특성에 미치는 영향
현도빈,오태성,하헌필,황종승 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.1
The thermoelectric properties of the p-type 22.5% Bi₂Te₃-77.5% Sb₂Te₃ single crystals, grown by the zone melting method, have been studied with changing the amount of excess Te up to 6 wt% and the growth rate from 0.1 to 0.5 ㎜/min. The Seebeck coefficient and electrical resistivity along the ingot growth direction were significantly affected by the amount of excess Te and growth rate due to the retrograde solubility of Te and the segregation of free Te in the matrix. The 5 wt% excess Te-doped 22.5% Bi₂Te₃-77.5% Sb₂Te₃ single crystal, grown at 0.1 ㎜/min, exhibited a figure-of-merit higher than 3.2×10^(-3)/K. However, the figure-of-merit at the last frozen part of such ingot decreased significantly due to the segregation of free Te. With charging 5 wt% excess Te-doped 22.5% Bi₂Te₃-77.5% Sb₂Te₃ at the first-to-freeze part and 0.2 wt% Te-deficient 22.5% Bi₂Te₃-77.5% Sb₂Te₃ at the last-to-freeze part, p-type single crystals with the figure-of-merit higher than 3.2×10^(-3)/K throughout the whole ingot were obtained.