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22. Effect of Microstructures on Exchange Anisotropy in Mn-Ir/Ni-Fe Exchange-Biased Multilayers with Various Stacking Structures

Author

Ro, Jae-Chul, Choi, Young-Suk, Suh, Su-Jung, and Lee, Hwack-Joo

Subjects
Magnetism -- Research, Crystals -- Research, Anisotropy -- Research, Business, Electronics, Electronics and electrical industries
Abstract

The magnetic properties and the microstructures of the Mn-Ir/Ni-Fe multilayers with various stacking structures and buffer layer materials have been investigated. The (111) texture of Mn-Ir/Ni-Fe is obtained in the top structures with Ta or Zr buffer. However, all multilayers which contain Mn-Ir films deposited on Ni-Fe films exhibit high [H.sub.ex], regardless of the (111) preferred orientation of Mn-Ir film. The TS multilayers which show high [H.sub.ex] have large Mn-Ir grains at the interface, compared with BS multilayers without exchange anisotropy. The multilayers which reveal the exchange anisotropy also have the groin-to-grain epitaxial tendency at interface of Mn-Ir/Ni-Fe. It is concluded that the [H.sub.ex] is not related to the (111) texture of the Mn-Ir film, but related to the grain size of the Mn-Ir film and the morphology at the interface between the Mn-Ir and the Ni-Fe grains. Key word--Mn-Ir/Ni-Fe, stacking structure, buffer layer, (111) texture, [H.sub.ex], epitaxial tendency, the grain size of Mn-Ir

Published
1999

49. Low-Temperature Sintering and Piezoelectric Properties of CuO-Added KNbO3 Ceramics.

Author

Kim, Dae ‐ Hyeon, Joung, Mi ‐ Ri, Seo, In ‐ Tae, Hur, Joon, Kim, Jong ‐ Hyun, Kim, Bo ‐ Yun, Lee, Hwack ‐ Joo, Nahm, Sahn, and Damjanovic, D.

Subjects
LOW temperatures, SINTERING, COPPER oxide, POTASSIUM niobate, PIEZOELECTRIC ceramics, DIELECTRIC properties, COPPER ions
Abstract

Dielectric and piezoelectric properties of CuO-added KNbO3 ( KN) ceramics were investigated. The CuO reacted with the Nb2 O5, formed a CuO- Nb2 O5-related liquid phase during the sintering, and assisted the densification of the KN ceramics at low temperatures. Moreover, some of the Cu2+ ions replaced the Nb5+ ions in the matrix and behaved as a hardener. The dielectric and piezoelectric properties of the KN ceramics were considerably influenced by the relative density. The 1.0 mol% CuO-added KN ceramic sintered at 960°C for 1.0 h, which showed a maximum relative density, exhibited a high phase angle of 86.9°, Pr of 14.8 μC/cm2, and Ec of 1.8 kV/mm. This specimen also exhibited good dielectric and piezoelectric properties: εT33 /εo of 364, d33 of 122 pC/N, kp of 0.29, and Qm of 611. [ABSTRACT FROM AUTHOR]

Published
2014
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