Dynamics of domain walls with lines in rare-earth orthoferrites in magnetic and electric fields with exchange relaxation processes taken into account

2003 ◽  
Vol 29 (8) ◽  
pp. 657-662 ◽  
Author(s):  
E. G. Ekomasov
Keyword(s):  
Rare Earth ◽  
Electric Fields ◽  
Domain Walls ◽  
Relaxation Processes

Conduction Electron Contributions to the Crystalline Electric Fields in Transition Metals

1974 ◽  
Vol 52 (11) ◽  
pp. 985-988 ◽  
Author(s):  
A. Ludwig ◽  
R. A. B. Devine
Keyword(s):  
Rare Earth ◽  
Transition Metals ◽  
Noble Metal ◽  
Electric Fields ◽  
Conduction Electron ◽  
Point Charge ◽  
Rare Earth Ions ◽  
Negative Point ◽  
Tentative Explanation ◽  
Crystalline Electric Fields

We discuss the origin of the crystalline electric fields for rare earth ions in transition and noble metal hosts, in terms of the band character of the host material and of localization and delocalization of 5d electrons on the rare earth ions. A tentative explanation is given for the almost pure negative point charge character found in Pd and Pt.

scholarly journals Stiffness in vortex—like structures due to chirality-domains within a coupled helical rare-earth superlattice

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Amitesh Paul
Keyword(s):  
Rare Earth ◽  
Domain Walls ◽  
Topological Defects ◽  
Magnetic Ordering ◽  
Direct Consequence ◽  
Magnetic Vortex ◽  
Range Magnetic Order ◽  
Wide Range ◽  
Out Of Plane ◽  
The Stability

Abstract Vortex domain walls poses chirality or ‘handedness’ which can be exploited to act as memory units by changing their polarity with electric field or driving/manupulating the vortex itself by electric currents in multiferroics. Recently, domain walls formed by one dimensional array of vortex—like structures have been theoretically predicted to exist in disordered rare-earth helical magnets with topological defects. Here, in this report, we have used a combination of two rare-earth metals, e.g."Equation missing" superlattice that leads to long range magnetic order despite their competing anisotropies along the out-of-plane (Er) and in-plane (Tb) directions. Probing the vertically correlated magnetic structures by off-specular polarized neutron scattering we confirm the existence of such magnetic vortex—like domains associated with magnetic helical ordering within the Er layers. The vortex—like structures are predicted to have opposite chirality, side—by—side and are fairly unaffected by the introduction of magnetic ordering between the interfacial Tb layers and also with the increase in magnetic field which is a direct consequence of screening of the vorticity in the system due to a helical background. Overall, the stability of these vortices over a wide range of temperatures, fields and interfacial coupling, opens up the opportunity for fundamental chiral spintronics in unconventional systems.

Supersonic nonlinear dynamics of domain walls in rare-earth orthoferrites

2003 ◽  
Vol 263 (1-2) ◽  
pp. 113-120 ◽  
Author(s):  
A.P. Kuz’menko ◽  
A.V. Kaminsky ◽  
M.B. Dobromyslov
Keyword(s):  
Nonlinear Dynamics ◽  
Rare Earth ◽  
Domain Walls

Displacement Charge Patterns and Ferroelectric Domain Wall Dynamics Studied by In-Situ Tem

1999 ◽  
Vol 596 ◽  
Author(s):  
A. Krishnan ◽  
M. M. J. Treacy ◽  
M. E. Bisher ◽  
P. Chandra ◽  
P. B. Littlewood
Keyword(s):  
Electric Fields ◽  
Domain Walls ◽  
Energy State ◽  
Ferroelectric Domain ◽  
Potassium Niobate ◽  
In Situ Tem ◽  
Domain Wall Dynamics ◽  
Transmission Electron ◽  
Energy Domain

AbstractWe have observed the growth of domains in ferroelectric barium titanate and potassium niobate using a transmission electron microscope. When domains move in response to electric fields we see a scaling effect where the fine scale domain structure is activated first, followed by larger length-scale patterns. Curvature and tilting of domain walls leads to local uncompensated displacement charge and external fields can interact with these charged walls. In this paper, we posit that the presence of displacement charge on domain walls is important for polarization switching. Charge-neutral domain configurations are in a lower energy state and are harder to switch. We argue that the number of charge-neutral, low energy domain configurations can increase with time. This mechanism provides an intrinsic contribution to ferroelectric fatigue.

scholarly journals Исследование релаксационных и переходных процессов в сегнетопьезокерамике с использованием метода импедансной спектроскопии

2020 ◽  
Vol 46 (8) ◽  
pp. 14
Author(s):  
И.А. Швецов ◽  
М.А. Луговая ◽  
Н.А. Швецова ◽  
Е.И. Петрова ◽  
А.Н. Рыбянец
Keyword(s):  
Comparative Analysis ◽  
Impedance Spectroscopy ◽  
Electric Fields ◽  
Physical Interpretation ◽  
Dielectric Constants ◽  
Ferroelectric Ceramics ◽  
Precision Measurements ◽  
Relaxation Processes ◽  
Dc Electric Field

A new method for studying relaxation and transient processes in ferroelectric ceramics under the influence of dc electric field is proposed. Precision measurements of time dependences of complex dielectric constants of ferroelectric ceramics in the region of weak electric fields were carried out using the method of impedance spectroscopy. A comparative analysis of various methods for characterization of relaxation processes in ferroelectric ceramics is carried out. A physical interpretation of the results is proposed.

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