Magnetic Domain-Wall Induced Electric Polarization in NdCrO3 Polycrystalline Ceramic

We reported the magnetic, dielectric and magnetoelectric properties of NdCrO3 polycrystalline ceramics. Magnetization curves revealed two magnetic transitions at 227 K and 38 K, which corresponded to Cr3+ canted antiferromagnetic ordering and Cr3+ spin reorientation phase transition, respectively. At 11.5 K, a Schottky-type anomaly was observed, caused by Nd3+ ground doublet Zeeman splitting. High-temperature dielectric relaxation exhibited a type of thermally activated relaxation process, which mainly resulted from the Maxwell–Wagner effect. The spin-reorientation of Cr3+ ions and the Nd3+ ground doublet splitting were observed to be accompanied by an electric polarization. The polarization could be induced by the presence of the antiferromagnetic-type domain walls, which led to spatial inversion symmetry breaking.

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Ferroelectric and Magnetic Domain Walls in High Temperature Multiferroic Films and Heterostructures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.845.7 ◽

2016 ◽

Vol 845 ◽

pp. 7-12

Author(s):

Z.V. Gareeva ◽

A.K. Zvezdin ◽

T.T. Gareev

Keyword(s):

High Temperature ◽

Domain Walls ◽

Bismuth Ferrite ◽

Magnetic Domain ◽

Short Review ◽

Electric Polarization ◽

Pinning Effect ◽

Iron Garnets ◽

Magnetic Domain Walls ◽

Multiferroic Films

In the last decade, considerable attention has been focused on the search of new multiferroic materials and the ways of improvement of their magnetoelectric properties. In this short review, we survey the progress in study of multiferroics focusing the high temperature multiferroic bismuth ferrite and rare earth iron garnets. We discuss the recent results of investigation of domain walls in multiferroics, concentrating the most important magnetoelectric manifestations (electric polarization and magnetization), and the pinning effect appearing as clamping of ferroelectric and magnetic domain walls.

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Creep Motion of Elastic Interfaces Driven in a Disordered Landscape

Annual Review of Condensed Matter Physics ◽

10.1146/annurev-conmatphys-031119-050725 ◽

2021 ◽

Vol 12 (1) ◽

pp. 111-134

Author(s):

Ezequiel E. Ferrero ◽

Laura Foini ◽

Thierry Giamarchi ◽

Alejandro B. Kolton ◽

Alberto Rosso

Keyword(s):

Disordered Systems ◽

Domain Walls ◽

Magnetic Domain ◽

Large Family ◽

Critical Threshold ◽

Mean Velocity ◽

Thermally Activated ◽

Physical Picture ◽

Magnetic Domain Walls ◽

Elastic Interface

The thermally activated creep motion of an elastic interface weakly driven on a disordered landscape is one of the best examples of glassy universal dynamics. Its understanding has evolved over the past 30 years thanks to a fruitful interplay among elegant scaling arguments, sophisticated analytical calculations, efficient optimization algorithms, and creative experiments. In this article, starting from the pioneer arguments, we review the main theoretical and experimental results that lead to the current physical picture of the creep regime. In particular, we discuss recent works unveiling the collective nature of such ultraslow motion in terms of elementary activated events. We show that these events control the mean velocity of the interface and cluster into “creep avalanches” statistically similar to the deterministic avalanches observed at the depinning critical threshold. The associated spatiotemporal patterns of activated events have been recently observed in experiments with magnetic domain walls. The emergent physical picture is expected to be relevant for a large family of disordered systems presenting thermally activated dynamics.

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Electric polarization of magnetic domain walls in magnetoelectrics

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/27/24/246002 ◽

2015 ◽

Vol 27 (24) ◽

pp. 246002 ◽

Cited By ~ 4

Author(s):

I P Lobzenko ◽

P P Goncharov ◽

N V Ter-Oganessian

Keyword(s):

Domain Walls ◽

Magnetic Domain ◽

Electric Polarization ◽

Magnetic Domain Walls

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Spin Flexoelectricity and New Aspects of Micromagnetism

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.67.149 ◽

2010 ◽

Vol 67 ◽

pp. 149-157 ◽

Cited By ~ 1

Author(s):

Alexander P. Pyatakov ◽

Anatoly K. Zvezdin ◽

D.A. Sechin ◽

A.S. Sergeev ◽

E.P. Nikolaeva ◽

...

Keyword(s):

Domain Walls ◽

Magnetic Domain ◽

Domain Wall Motion ◽

Electric Polarization ◽

Magnetic Media ◽

Magnetic Domain Wall ◽

Magnetic Vortices ◽

Electrical Control ◽

Magnetic Domain Walls ◽

Physical Phenomena

The coupling between the strain gradient and electric polarization is known as flexoelectricity in dielectrics materials. In case of magnetic media it takes the form of electric polarization induced by spin modulation and vice versa. This spin flexoelectricity causes new physical phenomena of micromagnetism such as electric field driven magnetic domain wall motion and electrical control of magnetic vortices in magnets as well as clamping of the magnetic domain walls at the ferroelectric ones in multiferroics.

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The direct determination of magnetic domain wall profiles using a split detector STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109471 ◽

1978 ◽

Vol 36 (1) ◽

pp. 466-467

Author(s):

J.N. Chapman ◽

P.E. Batson ◽

E.M. Waddell ◽

R.P. Ferrier

Keyword(s):

Electron Microscope ◽

Domain Wall ◽

Transmission Electron Microscope ◽

Domain Walls ◽

Photographic Plate ◽

Magnetic Domain ◽

Direct Determination ◽

Quantitative Information ◽

Scanning Transmission Electron Microscope ◽

Transmission Electron

By far the most commonly used mode of Lorentz microscopy in the examination of ferromagnetic thin films is the Fresnel or defocus mode. Use of this mode in the conventional transmission electron microscope (CTEM) is straightforward and immediately reveals the existence of all domain walls present. However, if such quantitative information as the domain wall profile is required, the technique suffers from several disadvantages. These include the inability to directly observe fine image detail on the viewing screen because of the stringent illumination coherence requirements, the difficulty of accurately translating part of a photographic plate into quantitative electron intensity data, and, perhaps most severe, the difficulty of interpreting this data. One solution to the first-named problem is to use a CTEM equipped with a field emission gun (FEG) (Inoue, Harada and Yamamoto 1977) whilst a second is to use the equivalent mode of image formation in a scanning transmission electron microscope (STEM) (Chapman, Batson, Waddell, Ferrier and Craven 1977), a technique which largely overcomes the second-named problem as well.

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Lorentz microscopy study of magnetic domain walls in Fe-Cr-Co alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109458 ◽

1978 ◽

Vol 36 (1) ◽

pp. 462-463

Author(s):

Yalcin Belli

Keyword(s):

Domain Walls ◽

Magnetic Domain ◽

Microscopy Study ◽

Ferromagnetic Phase ◽

Stable Phase ◽

Magnetic Domains ◽

Lorentz Microscopy ◽

Magnetic Hardening ◽

Electron Microscopes ◽

Co Alloys

Fe-Cr-Co alloys have great technological potential to replace Alnico alloys as hard magnets. The relationship between the microstructures and the magnetic properties has been recently established for some of these alloys. The magnetic hardening has been attributed to the decomposition of the high temperature stable phase (α) into an elongated Fe-rich ferromagnetic phase (α1) and a weakly magnetic or non-magnetic Cr-rich phase (α2). The relationships between magnetic domains and domain walls and these different phases are yet to be understood. The TEM has been used to ascertain the mechanism of magnetic hardening for the first time in these alloys. The present paper describes the magnetic domain structure and the magnetization reversal processes in some of these multiphase materials. Microstructures to change properties resulting from, (i) isothermal aging, (ii) thermomagnetic treatment (TMT) and (iii) TMT + stepaging have been chosen for this investigation. The Jem-7A and Philips EM-301 transmission electron microscopes operating at 100 kV have been used for the Lorentz microscopy study of the magnetic domains and their interactions with the finely dispersed precipitate phases.

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Temperature Dependence of Magnetic Domains and Wall Structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009573x ◽

1972 ◽

Vol 30 ◽

pp. 496-497

Author(s):

Sonoko Tsukahara ◽

Tadami Taoka ◽

Hisao Nishizawa

Keyword(s):

Temperature Dependence ◽

Domain Walls ◽

Magnetic Domain ◽

Iron Film ◽

Objective Lens ◽

Lorentz Microscopy ◽

Domain Structures ◽

Wall Structures ◽

Crystal Films ◽

Metallurgical Structure

The high voltage Lorentz microscopy was successfully used to observe changes with temperature; of domain structures and metallurgical structures in an iron film set on the hot stage combined with a goniometer. The microscope used was the JEM-1000 EM which was operated with the objective lens current cut off to eliminate the magnetic field in the specimen position. Single crystal films with an (001) plane were prepared by the epitaxial growth of evaporated iron on a cleaved (001) plane of a rocksalt substrate. They had a uniform thickness from 1000 to 7000 Å.The figure shows the temperature dependence of magnetic domain structure with its corresponding deflection pattern and metallurgical structure observed in a 4500 Å iron film. In general, with increase of temperature, the straight domain walls decrease in their width (at 400°C), curve in an iregular shape (600°C) and then vanish (790°C). The ripple structures with cross-tie walls are observed below the Curie temperature.

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