Domain Structure in Thin FeNiCo Films with In-Plane Anisotropy

Magnetic colloid observations on synthetic hematite indicate the existence of only two phase domain structures. The normal or N structure is a usually slablike 180° wall structure where the majority of walls are parallel to the basal plane and have a 100–200 μm separation. Wall energies are estimated to be 0.35 × 10−1 to 1.0 × 10−1 erg/cm2 from domain geometry. Under special circumstances, a domain structure, called CN domains, occurs in [Formula: see text] and [Formula: see text] surfaces and appears to be a two phase structure of non-180° walls. Spontaneous magnetostriction requires these walls of 100–200 μm separation to be planar and lie either perpendicular to or at ~26° to the basal plane. A third structure, called C domains, of 25–50 μm spaced planar walls occurs on (110) surfaces in two characteristic directions symmetric with the basal plane and consistent with CN-wall geometry. However, because of their behavior and geometry, they appear to be nonmagnetically stabilized but possibly by a strain effect. By using magnetoelastic coupling for the effective basal plane anisotropy constant for moment rotation in domain walls, N-wall energies are estimated to be 0.45 × 10−1 to 1.0 × 10−1 erg/cm2. Because of geometry complications CN-wall energies are difficult to calculate but are estimated to be ~10−1 erg/cm2 or slightly larger.

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Domains and domain nucleation in magnetron-sputtered CoCr thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151064 ◽

1993 ◽

Vol 51 ◽

pp. 1046-1047

Author(s):

B. G. Demczyk

Keyword(s):

Thin Films ◽

Domain Structure ◽

Magnetic Domain ◽

Domain Size ◽

Film Plane ◽

Magnetic Domain Structure ◽

Perpendicular Magnetization ◽

Columnar Grains ◽

Reversal Mechanism ◽

Lorentz Transmission Electron Microscopy

CoCr thin films have been of interest for a number of years due to their strong perpendicular anisotropy, favoring magnetization normal to the film plane. The microstructure and magnetic properties of CoCr films prepared by both rf and magnetron sputtering have been examined in detail. By comparison, however, relatively few systematic studies of the magnetic domain structure and its relation to the observed film microstructure have been reported. In addition, questions still remain as to the operative magnetization reversal mechanism in different film thickness regimes. In this work, the magnetic domain structure in magnetron sputtered Co-22 at.%Cr thin films of known microstructure were examined by Lorentz transmission electron microscopy. Additionally, domain nucleation studies were undertaken via in-situ heating experiments.It was found that the 50 nm thick films, which are comprised of columnar grains, display a “dot” type domain configuration (Figure 1d), characteristic of a perpendicular magnetization. The domain size was found to be on the order of a few structural columns in diameter.

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Ferroelectric Domain Structure of Pb(Zr.52Ti.48)03

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000933 ◽

1980 ◽

Vol 38 ◽

pp. 214-215

Author(s):

E.K. Goo ◽

R.K. Mishra

Keyword(s):

Phase Transformation ◽

Domain Structure ◽

Tetragonal Phase ◽

Ferroelectric Domain ◽

Cubic Phase ◽

Ion Milling ◽

Thin Foils ◽

Ferroelectric Domain Structure ◽

Ferroelectric Domains

Ferroelectric domains are twins that are formed when PZT undergoes a phase transformation from a non-ferroelectric cubic phase to a ferroelectric tetragonal phase upon cooling below ∼375°C.,1 The tetragonal phase is spontaneously polarized in the direction of c-axis, making each twin a ferroelectric domain. Thin foils of polycrystalline Pb (Zr.52Ti.48)03 were made by ion milling and observed in the Philips EM301 with a double tilt stage.

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