http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Chau, N.,The, N.D.,Hoa, N.Q.,Huu, C.X.,Tho, N.D.,Yu, S.-C. Elsevier 2007 Materials science & engineering. properties, micro Vol.449 No.-
<P><B>Abstract</B></P><P>A large number of amorphous ribbons based on Finemet have been prepared by rapid quenching on a single copper wheel with linear speed of <I>v</I>=25–30m/s. The ribbons are 20–25μm thick and 6–8mm wide. All as-cast samples are amorphous. Two criteria producing the colossal magnetocaloric effect (CMCE) in magnetic materials working as magnetic refrigerants are high saturation magnetization and sharp ferromagnetic–paramagnetic phase transition. The Fe-based amorphous ribbons fit these cretia. Thermomagnetic curves as well as isothermal magnetization curves around the Curie temperature of all the studied samples have been determined. The results show that the magnetic entropy change, |Δ<I>S</I><SUB>m</SUB>|, belongs to a class of materials with CMCE and the |Δ<I>S</I><SUB>m</SUB>|<SUB>max</SUB> values have been obtained at a moderately low magnetic field change of 1.35T, moreover |Δ<I>S</I><SUB>m</SUB>|<SUB>max</SUB> occurred at quite high temperature.</P>
Hoa, N.Q.,Chau, N.,Yu, S.-C.,Thang, T.M.,The, N.D.,Tho, N.D. Elsevier Sequoia 2007 Materials science & engineering Structural materia Vol.449 No.-
<P><B>Abstract</B></P><P>The structure, crystallization and magnetic properties of ribbons obtained by first making amorphous ribbons and then objecting them to a crystallization annealing have been published elsewhere by us previously. In the present work the soft magnetic ribbons Fe<SUB>73.5−<I>x</I></SUB>Cr<SUB><I>x</I></SUB>Si<SUB>13.5</SUB>B<SUB>9</SUB>Nb<SUB>3</SUB>Au<SUB>1</SUB> (numbers indicate at.%, <I>x</I>=1–5) are prepared by fast quenching on a single copper wheel. X-ray diffraction patterns show that the as-cast samples are amorphous. Differential scanning calorimetry analysis indicates that the crystallization temperature of the α-Fe(Si) phase is a little higher than that of pure Finemet. With the same annealing conditions, the crystallization volume fraction decreases with increasing Cr content substituted for Fe. Hysteresis loops of as-cast samples measured by Permagraph show that domain walls are pinned. After appropriate annealing, the ultrasoft magnetic properties of nanocomposite materials are established. The magnetic entropy change, |Δ<I>S</I><SUB>m</SUB>|, of studied samples has been determined, and a giant magnetocaloric effect is found. Our materials could be considered as promising magnetic refrigerants working at high temperatures (several hundreds °C).</P>
Tho, P.T.,Clements, E.M.,Kim, D.H.,Tran, N.,Osofsky, M.S.,Phan, M.H.,Phan, T.L.,Lee, B.W. Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.741 No.-
<P><B>Abstract</B></P> <P>We have studied the crystal structure and magnetic properties of Bi<SUB>0.84</SUB>La<SUB>0.16</SUB>Fe<SUB>1-x</SUB>Ti<SUB>x</SUB>O<SUB>3</SUB> (<I>x</I> = 0.02–0.1) at the morphotropic phase boundary of <I>R</I>3<I>c</I>, <I>Imma</I>, and <I>Pbam</I> phases. The results of Rietveld-refined X-ray diffraction patterns reveal the existence of multi-phase structures, including <I>R</I>3<I>c</I> + <I>Imma</I> for <I>x</I> = 0.02–0.06 and <I>Imma + Pbam</I> for <I>x</I> = 0.08–0.1. The studies of Raman scattering spectra indicate a structural transformation through the disappearance of typical <I>R</I>3<I>c</I> modes. This strongly influences the magnetic properties that are dependent on the crystalline phase ratio. In particular, the magnetic coercivity of <I>x</I> = 0.04–0.06 drastically changes when the <I>Imma</I> phase is dominant. A mechanism of magnetic interactions occurring at the phase boundary is proposed to explain the features of magnetic hysteresis loops of the compounds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crystal structure of (La,Ti)-codoped BiFeO<SUB>3</SUB> at morphotropic phase boundary. </LI> <LI> Magnetic properties are strongly dependent on the phase ratio of two crystal structures. </LI> <LI> Magnetic interactions at the phase boundary were explained. </LI> <LI> The vertical hysteresis shift (exchange bias) is related to the pinned spin at the phase boundary. </LI> </UL> </P>
Tho, P.T.,Kim, D.H.,Phan, T.L.,Dang, N.V.,Lee, B.W. Elsevier 2018 Journal of magnetism and magnetic materials Vol.462 No.-
<P><B>Abstract</B></P> <P>We have studied the vertical hysteresis shift, the exchange bias, and the exchange spring effect in a polycrystalline sample of Bi<SUB>0.84</SUB>La<SUB>0.16</SUB>Fe<SUB>0.96</SUB>Ti<SUB>0.04</SUB>O<SUB>3</SUB> at morphotropic phase boundary. The magnetic coupling at the phase boundary causes the formation of pinned spin region, which induces the spin rotation inside the two structural phases. The exchange coupling between the pinned spin and the two phases act as hard/soft coupling layers, respectively. Dependence on the strength of the spin pinning, we observed various types of the exchange coupling at different temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The phase boundary is directly separated two crystal structures into two grain size regions. </LI> <LI> High-temperature magnetic measurement is used to study the magnetic properties and magnetic interactions. </LI> <LI> The vertical hysteresis shift, the exchange bias, and the exchange spring effects are observed at different temperature and applied field conditions. </LI> <LI> The spin pinning at the phase boundary is explained for the various types of magnetic coupling and hysteresis behaviors. </LI> </UL> </P>
Giant magnetoimpedance effect in nanocrystalline Fe73.5-xMnxSi13.5B9Nb₃Cu₁(x=1, 3, 5) alloys
L.A. Tuan,N.D. Ha,C.O. Kim,N.D. Tho,H.B. Lee 한국자기학회 2005 한국자기학회 학술연구발표회 논문개요집 Vol.15 No.1
The giant magnetoimpedance (GMI) of Fe_(73.5-x)Mn_xSi_(13.5)B_9Nb₃Cu₁ (x= 1, 3, 5) alloys prepared by a rapid quenching technique has been measured to investigate the influence of the structural changes in the crystallization process as well as the changes of the soft magnetic properties such as permeability, coercivity, magnetic anisotropy, etc. after thermal treatment. Magnetoimpedance ratio (MIR) and incremental permeability ratio (PR) measurements were investigated in the frequency range of 1-10 ㎒ and at a fixed current of 10 ㎃. Ultrasoft magnetic behavior has been observed in the samples annealed at 560℃. The PR curves become narrower and sharper after heat treatment due to the decrease of anisotropy. The MIR and PR coincided with the softness of the magnetic properties of the thermally treated samples.