http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Preparation and thermoelectric properties of AgPb18SbTe20−xSex (x = 1, 2, 4) materials
H. Li,K.F. Cai,Y. Du,H.F. Wang,S.Z. Shen,X.L. Li,C.W. Zhou,Y.Y. Wang 한국물리학회 2012 Current Applied Physics Vol.12 No.1
AgPb18SbTe20xSex (x ¼ 1, 2, 4) bulk materials were prepared by combining hydrothermal synthesis and melting. Thermoelectric properties were measured from room temperature up to 773K. The materials showed n-type conduction and exhibited degenerate semiconductor behavior. The power factors of the materials varied greatly with increase of Se content (x). Partial substitution of Se for Te in AgPb18SbTe20resulted in remarkable reduction of thermal conductivity in the whole temperature range and increase of power factor at lower temperatures; therefore, the dimensionless figure of merit, ZT, was enhanced below 600K. A maximum ZT value of w0.82 is obtained at 523K for the AgPb18SbTe18Se2 sample.
K. W. Shao,W. H. Zhou,K. Gao,X. G. Zhu,P. Jia,Y. Li 대한금속ᆞ재료학회 2023 METALS AND MATERIALS International Vol.29 No.2
Catastrophic brittle failure prevents the application of bulk metallic glasses (BMGs).The brittle La69Co17Al14BMG showslarge compressive plasticity when compressed in constrained conditions. Here the compressive plasticity of this BMG wassystematically studied by decreasing aspect ratio (height/diameter) of the samples in uniaxial compression and the brittleductiletransition occurs at an aspect ratio of 0.36. With the increase of the plasticity (decrease of the aspect ratio), the hardnessdecreases firstly and then increases, however, the relaxation enthalpy indicating its structure increases monotonically. Our findings provide a powerful experimental support for the application of brittle La-based BMGs.
Wang, M.,Zhang, H.,Li, L.,Liu, X.,Hong, F.,Li, R.,Song, H.,Gui, M.,Shen, J.,Zhu, W.,Wang, J.,Zhou, L.,Jeong, J.H. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.585 No.-
Eu<SUP>3+</SUP> activated micrometer Y<SUB>2</SUB>MoO<SUB>6</SUB> phosphors with strong red emission bands, under a broad-band excitation wavelength range of 340-400nm, have been prepared by solid-state reaction and sol-gel technique. The photoluminescence indicates that the materials exhibit a characteristic red emission peak of Eu<SUP>3+</SUP> ions at 612nm. Compared with the material obtained by sol-gel method, the Y<SUB>2</SUB>MoO<SUB>6</SUB>:Eu prepared using solid state method showed much stronger red emission under the n-UV excitation. The broad excitation bands are assigned to charge transfer (CT) bands originating from the ligands (O) to the central ions Mo<SUP>6+</SUP>. About 12nm shift of excitation bands in Y<SUB>2</SUB>MoO<SUB>6</SUB>:Eu was found. With a decrease of the crystalline size, the excitation bands of O-Mo CT shift to the short wavelength. The origin of CT shift in macromaterial Y<SUB>2</SUB>MoO<SUB>6</SUB>:Eu was investigated quantitatively from the chemical bond viewpoint. All constituent chemical bonds in the crystal with or without oxygen vacancy were considered. The changes of average energy gap of the chemical bond Mo-O and the environmental factor (h<SUB>e</SUB>) surrounding Mo<SUP>6+</SUP> ions in the crystals were discussed quantitatively. Calculated results from two different methods analysis specifications showed that the origin of CT blue-shifts mainly come from the vacancies of O6 sites within the crystals.