Journal ArticleDOI
Possible Species of Ferromagnetic, Ferroelectric, and Ferroelastic Crystals
TLDR
In this paper, a determination is made of all possible species of full ferromagnetic, partial ferromagnetics, full ferroelectrics, partial magnetization vector, spontaneous polarization vector, or spontaneous strain tensor, and it is found out in which of these species two or all of the three types should couple completely or incompletely with each other.Abstract:
A ferromagnetic, ferroelectric, or ferroelastic crystal is called full or partial, according to whether all or not all but some of its orientation states are different in spontaneous magnetization vector, spontaneous polarization vector, or spontaneous strain tensor. In previous theories \char22{} for nonmagnetic crystals \char22{} the concept of "species" was introduced, a determination was made of all possible species of full ferroelectrics and of full ferroelastics, and those species were found in which ferroelectricity and ferroelasticity coexist and completely couple with each other. These theories are now extended to cover magnetic crystals in addition to nonmagnetic crystals and to cover the partial in addition to the full. A determination is made of all possible species of full ferromagnetics, partial ferromagnetics, full ferroelectrics, partial ferroelectrics, full ferroelastics, and partial ferroelastics, and it is found out in which of these species two or all of ferromagnetism, ferroelectricity, and ferroelasticity should couple completely or incompletely with each other.read more
Citations
More filters
Journal ArticleDOI
Revival of the Magnetoelectric Effect
Abstract: Recent research activities on the linear magnetoelectric (ME) effect?induction of magnetization by an electric field or of polarization by a magnetic field?are reviewed. Beginning with a brief summary of the history of the ME effect since its prediction in 1894, the paper focuses on the present revival of the effect. Two major sources for 'large' ME effects are identified. (i) In composite materials the ME effect is generated as a product property of a magnetostrictive and a piezoelectric compound. A linear ME polarization is induced by a weak ac magnetic field oscillating in the presence of a strong dc bias field. The ME effect is large if the ME coefficient coupling the magnetic and electric fields is large. Experiments on sintered granular composites and on laminated layers of the constituents as well as theories on the interaction between the constituents are described. In the vicinity of electromechanical resonances a ME voltage coefficient of up to 90?V?cm?1?Oe?1 is achieved, which exceeds the ME response of single-phase compounds by 3?5 orders of magnitude. Microwave devices, sensors, transducers and heterogeneous read/write devices are among the suggested technical implementations of the composite ME effect. (ii) In multiferroics the internal magnetic and/or electric fields are enhanced by the presence of multiple long-range ordering. The ME effect is strong enough to trigger magnetic or electrical phase transitions. ME effects in multiferroics are thus 'large' if the corresponding contribution to the free energy is large. Clamped ME switching of electrical and magnetic domains, ferroelectric reorientation induced by applied magnetic fields and induction of ferromagnetic ordering in applied electric fields were observed. Mechanisms favouring multiferroicity are summarized, and multiferroics in reduced dimensions are discussed. In addition to composites and multiferroics, novel and exotic manifestations of ME behaviour are investigated. This includes (i) optical second harmonic generation as a tool to study magnetic, electrical and ME properties in one setup and with access to domain structures; (ii) ME effects in colossal magnetoresistive manganites, superconductors and phosphates of the LiMPO4 type; (iii) the concept of the toroidal moment as manifestation of a ME dipole moment; (iv) pronounced ME effects in photonic crystals with a possibility of electromagnetic unidirectionality. The review concludes with a summary and an outlook to the future development of magnetoelectrics research.
Journal ArticleDOI
Observation of coupled magnetic and electric domains
TL;DR: Spatial maps of coupled antiferromagnetic and ferroelectric domains in YMnO3 are obtained by imaging with optical second harmonic generation and lead to a configuration that is dominated by the ferroelectromagnetic product of the order parameters.
Journal ArticleDOI
Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite
Claude Ederer,Nicola A. Spaldin +1 more
TL;DR: In this paper, the coupling between the ferroelectric and magnetic order parameters in the magnetoelectric multiferroic was analyzed using density functional theory within the local spin density approximation (LSDA) and the $\mathrm{LSDA}+\mathm{U}$ method.
Journal ArticleDOI
Domain wall nanoelectronics
Gustau Catalan,Jan Seidel,Jan Seidel,Jan Seidel,Ramamoorthy Ramesh,Ramamoorthy Ramesh,James F. Scott +6 more
TL;DR: In this paper, a review of magnetoelectric domain walls is presented, focusing on magneto-electrics and multiferroics but making comparisons where possible with magnetic domains and domain walls.
Journal ArticleDOI
REVIEWS OF TOPICAL PROBLEMS: Ferroelectromagnets
G. A. Smolenskiĭ,I. E. Chupis +1 more