ترغب بنشر مسار تعليمي؟ اضغط هنا

Converse Magnetoelectric Experiments on a Room Temperature Spirally Ordered Hexaferrite

76   0   0.0 ( 0 )
 نشر من قبل Khabat Ebnabbasi
 تاريخ النشر 2011
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Experiments have been performed to measure magnetoelectric properties of room temperature spirally ordered Sr3Co2Fe24O41 hexaferrite slabs. The measured properties include the magnetic permeability, the magnetization and the strain all as a function of the electric field E and the magnetic intensity H. The material hexaferrite Sr3Co2Fe24O41 exhibits broken symmetries for both time reversal and parity. The product of the two symmetries remains unbroken. This is the central feature of these magnetoelectric materials. A simple physical model is proposed to explain the magnetoelectric effect in these materials.

قيم البحث

اقرأ أيضاً

96 - S. Geprags , D. Mannix , M. Opel 2013
The quantitative understanding of converse magnetoelectric effects, i.e., the variation of the magnetization as a function of an applied electric field, in extrinsic multiferroic hybrids is a key prerequisite for the development of future spintronic devices. We present a detailed study of the strain-mediated converse magnetoelectric effect in ferrimagnetic Fe3O4 thin films on ferroelectric BaTiO3 substrates at room temperature. The experimental results are in excellent agreement with numerical simulation based on a two-region model. This demonstrates that the electric field induced changes of the magnetic state in the Fe3O4 thin film can be well described by the presence of two different ferroelastic domains in the BaTiO3 substrate, resulting in two differently strained regions in the Fe3O4 film with different magnetic properties. The two-region model allows to predict the converse magnetoelectric effects in multiferroic hybrid structures consisting of ferromagnetic thin films on ferroelastic substrates.
Ferromagnetic insulators (FMIs) are one of the most important components in developing dissipationless electronic and spintronic devices. However, since ferromagnetism generally accompanies metallicity, FMIs are innately rare to find in nature. Here, novel room-temperature FMI films are epitaxially synthesized by deliberate control of the ratio of two B-site cations in the double perovskite Sr2FeReO6. In contrast to the known ferromagnetic metallic phase in stoichiometric Sr2FeReO6, a FMI state with a high Curie temperature (Tc~400 K) and a large saturation magnetization (MS~1.8 {mu}B/f.u.) is found in highly cation-ordered Fe-rich phases. The stabilization of the FMI state is attributed to the formation of extra Fe3+-Fe3+ and Fe3+-Re6+ bonding states, which originate from the excess Fe. The emerging FMI state by controlling cations in the epitaxial oxide perovskites opens the door to developing novel oxide quantum materials & heterostructures.
Mutual control of the electricity and magnetism in terms of magnetic (H) and electric (E) fields, the magnetoelectric (ME) effect, offers versatile low power-consumption alternatives to current data storage, logic gate, and spintronic devices. Despit e its importance, E-field control over magnetization (M) with significant magnitude was observed only at low temperatures. Here we have successfully stabilized a simultaneously ferrimagnetic and ferroelectric phase in a Y-type hexaferrite single crystal up to T=450K and demonstrated the reversal of large non-volatile M by E field close to room temperature. Manipulation of the magnetic domains by E field is directly visualized at room temperature by using magnetic force microscopy. The present achievement provides an important step towards the application of bulk ME multiferroics.
The advent of long-range magnetic order in non-centrosymmetric compounds has stimulated interest in the possibility of exotic spin transport phenomena and topologically protected spin textures for applications in next-generation spintronics. This wor k reports a novel wurtzite-structure polar magnetic metal, identified as AA-stacked (Fe0.5Co0.5)5-xGeTe2, which exhibits a Neel-type skyrmion lattice as well as a Rashba-Edelstein effect at room temperature. Atomic resolution imaging of the structure reveals a structural transition as a function of Co-substitution, leading to the polar phase at 50% Co. This discovery reveals an unprecedented layered polar magnetic system for investigating intriguing spin topologies and ushers in a promising new framework for spintronics.
The oxide heterostructure [(YFeO$_3$)$_5$(LaFeO$_3$)$_5$]$_{40}$, which is magnetically ordered and piezoelectric at room temperature, has been constructed from two weak ferromagnetic AFeO$_3$ perovskites with different A cations using RHEED-monitore d pulsed laser deposition. The polarisation arises through the removal of inversion centres present within the individual AFeO$_3$ components. This symmetry reduction is a result of combining ordering on the A site, imposed by the periodicity of the grown structure, with appropriate orientations of the octahedral tilting characteristic of the perovskite units themselves, according to simple symmetry-controlled rules. The polarisation is robust against A site interdiffusion between the two layers which produces a sinusoidally modulated occupancy that retains the coupling of translational and point symmetries required to produce a polar structure. Magnetization and magneto-optical Kerr rotation measurements show that the heterostructures magnetic structure is similar to that of the individual components. Evidence of the polarity was obtained from second harmonic generation and piezoelectric force microscopy measurements. Modeling of the piezoresponse allows extraction of $d_{33}$ (approximately 10 pC/N) of the heterostructure, which is in agreement with DFT calculations.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا