http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
민성기(Seong-Gi Min),김경섭(Kyeong-Sup Kim),유성초(Seong-Cho Yu),문영모(Young-Mo Moon) 한국자기학회 2005 韓國磁氣學會誌 Vol.15 No.4
The magnetocaloric effect and magnetization behaviors have been studied for La_(1-x)PbxMnO₃ (x=0.1, 0.2, 0.3) alloys. The Curie temperature increased from 195 K to 352 K with increasing Pb concentration. A large magnetic entropy change (ΔS_M), which is calculated from H vs M curves associated with the ferromagnetic-paramagnetic transitions, has been observed. The maximum ΔS_M of La_(0.8)Pb_(0.2)MnO₃ was 1.22 J/㎏ K at 294 K for an applied field of 1.5 T. Adiabatic temperature change (ΔTαd) was measured directly by a special cryostat. The maximum ΔTαd of La_(0.7)Pb_(0.3)MnO₃ was 1.00 K at 352 K for an applied field of 2 T.
고온 초전도체 Y₁Ba₂Cu₃-xSnxO7-y의 자기적 특성 연구
이성규(Seong-Kyu Lee),이주일(Joo-Il Lee),김문석(Mun-Seog Kim),유성초(Seong-Cho Yu),임우영(Woo-Young Lim),백종성(Jong-Sung Beak) 한국자기학회 1991 韓國磁氣學會誌 Vol.1 No.2
The magnetic properties of the Y₁Ba₂Cu_(3-x)Sn_xO_(7-y) superconductor were studied as a function of Sn concentration by utilizing both the vibrating sample magnetometer (VSM) and torque magnetometer. Unlike the cases where Fe and Co were substituted for Cu, the superconducting transition temperature was maintained above 90 K until x reached the value of 0.36. The lower critical field H_(C1)(T) and upper critical field H_(C2)(T) are measured as a function of temperature and external magnetic field, respectively. By aid of these results, H_(C1)(0), H_(C2)(0), the coherence length ε_0, the penetration depth λ_0, and the Ginzburg-Landau parameter к were obtained. Flux pinning was also observed in the sample.
김동현(Dong-Hyun Kim),유성초(Seong-Cho Yu) 한국자기학회 2020 韓國磁氣學會誌 Vol.30 No.3
Magnetocaloric effect is observed for magnetic materials under external magnetic fields due to reduced magnetic entropy by being aligned along the applied field direction. Although it is discovered about 140 years ago, there are still many things to be explored. Here, we introduce basic concepts of magnetocaloric effect in terms of its relation with phase transition and thermodynamics. Various magnetocaloric materials are introduced with recent research trend to control structural/magnetic properties of those materials. Magnetocaloric effect for nanoparticles at cryogenic temperatures are introduced. Lastly, existence of magnetocaloric effect even on ultrafast fs- and ps timescale is discussed.
이희복(Heebok Lee),송인명(In-Myoung Song),유성초(Seong-Cho Yu),임우영(Woo-Young Lim) 한국자기학회 1993 韓國磁氣學會誌 Vol.3 No.3
The X-ray diffraction pattern of amorphous Fe_(78)Si_9B₁₃ alloy was analyzed to obtain the radial distribution function (RDF) where the first peak was in the form of Gaussian function. The calculated coordination number of the form of Gaussian function. The calculated coordination number of the sample is 13.5, the mean distance between near-neighbor atoms r_0 is 2.595 Å. and a Gaussian parametet δr indicating near-neighbor atomic distribution is 0.27 Å. The temperature dependence of saturated magnetization at low temperature could be explained by spin wave excitations theory yielding the spin wave stiffness constant as 117.8 meVŲ. Also, we tried to fit the observed temperature dependence of saturated magnetization with the Handrich's equation of the modified molecular field theory for the amorphous ferromagnet. Nice fittings are obtained when we used the parameters △=0.32(S=1 / 2) and △=0,23(S=1), respectively. Finally, the calculated spin wave stiffness constant using the parameters and the structural data are 149 meVŲ for S=1 / 2 and 138 meVŲ for S=1, respectively. The mean exchange coupling integral between near-neighbor atoms was estimated to be 17.9 meV for S=1 / 2 and 6.7 meV for S=1.