{"id":441,"date":"2020-01-16T15:26:10","date_gmt":"2020-01-16T18:26:10","guid":{"rendered":"http:\/\/bit7.com.br\/main\/?p=441"},"modified":"2020-01-16T15:26:10","modified_gmt":"2020-01-16T18:26:10","slug":"magnetismo-controlado-por-eletricidade","status":"publish","type":"post","link":"https:\/\/bit7.com.br\/main\/magnetismo-controlado-por-eletricidade\/","title":{"rendered":"Magnetismo controlado por eletricidade."},"content":{"rendered":"\n

A manipula\u00e7\u00e3o el\u00e9trica das propriedades magn\u00e9ticas \u00e9 um problema-chave da pesquisa de materiais. Para atender aos requisitos da eletr\u00f4nica moderna, esses processos devem ser alterados para altas frequ\u00eancias. Em materiais ferrosos, isso pode ser alcan\u00e7ado pelo controle el\u00e9trico e magn\u00e9tico de suas excita\u00e7\u00f5es fundamentais. <\/p>\n\n\n\n

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Electric and magnetic ordering in rare-earth iron borates. (a) Homogeneous distribution of Fe spins (blue arrows) in the ab plane and in the absence of static magnetic (H) and electric (E) fields. Different arrows refer to different domains in the sample. Both antiferromagnetic vector L and static polarization P equal zero in this case. (c),(d) Either magnetic field H\u2225b (c) or electric field E\u2191\u2191a (d) induce P\u2191\u2191a and L\u2225a. (e),(f) Rotation of the magnetic field to H\u2225a (e) or inversion of the electric field to E\u2191\u2193a (f) leads to the inversion of the static polarization and the rotation of the antiferromagnetic vector. Figure 1<\/a> shows the crystal structure of SmFe3(BO3)4 <\/figcaption><\/figure>\n\n\n\n

Aqui identificamos vibra\u00e7\u00f5es magn\u00e9ticas em boratos de ferro que s\u00e3o simultaneamente sens\u00edveis a campos el\u00e9tricos e magn\u00e9ticos externos. \u00c9 demonstrada quase 100% de modula\u00e7\u00e3o da radia\u00e7\u00e3o. <\/p>\n\n\n\n

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Manipulation of magnon excitation by magnetic field. (a) Suppression of the magnon at 9\u2009\u2009cm\u22121 in SmFe3(BO3)4 by external magnetic fields along the a axis. (b) Increasing of the mode intensity in magnetic fields H\u2225b axis. (c) Magnetic field dependence of the mode intensity from fitting the spectra in Figs. 2<\/a> and 2<\/a> by a Lorentzian function (blue and orange spheres, respectively) and from model calculation based on Eq. (2<\/a>) (solid gray lines ).<\/figcaption><\/figure>\n\n\n\n
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Manipulation of the magnon in SmFe3(BO3)4 by static electric field. (a) Transmittance amplitude and (b) phase shift spectra in the electric field. Symbols: green, initial state; blue, negative electric field; and red, positive electric field. The black line demonstrates that an external magnetic field can approximately compensate the effect of the electric field. (c) Direct modulation of the transmittance amplitude signal by a static electric field at different frequencies. The inset shows the temperature dependence of the resonance frequency as observed (dark gray line) and calculated (light gray line) in Ref. [62<\/a>]. The temperatures and frequencies of the transmittance amplitude measurements are marked in the inset by circles. (d) Changes in magnon contribution in the electric field. Symbols are experimental results, while the solid lines come from model calculation based on Eq. (2<\/a>). The orange and blue symbols correspond to a simultaneous application of electric and magnetic fields .<\/figcaption><\/figure>\n\n\n\n
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Electric field effect in NdFe3(BO3)4. (a) Temperature dependence of the relative transmittance amplitude signal for different frequencies. Weak sawtooth modulation of the curves is due to \u00b1500\u2009\u2009V sweeping of electric voltage during the cooling process. The inset shows the temperature dependence of the resonance frequency as observed (dark gray line) and calculated (light gray line) in Ref. [62<\/a>]. The temperatures and frequencies of the resonances seen in (a) are marked in the inset by circles. (b) An example of a detailed view of the data in (a). Here the spectra are normalized by the minimal transmitted intensity. (c) Direct modulation of the terahertz transmittance amplitude at selected frequencies in NdFe3(BO3)4
<\/figcaption><\/figure>\n\n\n\n

A alta sensibilidade pode ser explicada por uma modifica\u00e7\u00e3o da orienta\u00e7\u00e3o da rota\u00e7\u00e3o que controla as condi\u00e7\u00f5es de excita\u00e7\u00e3o em boratos ferrosos. Essas experi\u00eancias demonstram a possibilidade de alterar propriedades magn\u00e9ticas de materiais de forma independente por campos el\u00e9tricos e magn\u00e9ticos externos. <\/p>\n\n\n\n

Bibliografia:<\/strong><\/p>\n\n\n\n

<\/p>\n\n\n\n

site: https:\/\/www.inovacaotecnologica.com.br<\/a><\/p>\n\n\n\n

Artigo: Switching of Magnons by Electric and Magnetic Fields in Multiferroic Borates<\/em>
Autores: A. M. Kuzmenko, D. Szaller, Th. Kain, V. Dziom, L. Weymann, A. Shuvaev, Anna Pimenov, A. A. Mukhin, V. Yu. Ivanov, I. A. Gudim, L. N. Bezmaternykh, A. Pimenov
Revista: Physical Review Letters
Vol.: 120, 027203
DOI: 10.1103\/PhysRevLett.120.027203 <\/p>\n","protected":false},"excerpt":{"rendered":"

A manipula\u00e7\u00e3o el\u00e9trica das propriedades magn\u00e9ticas \u00e9 um problema-chave da pesquisa de materiais. Para atender aos requisitos da eletr\u00f4nica moderna, esses processos devem ser alterados para altas frequ\u00eancias. Em materiais ferrosos, isso pode ser alcan\u00e7ado pelo controle el\u00e9trico e magn\u00e9tico de suas excita\u00e7\u00f5es fundamentais. Aqui identificamos vibra\u00e7\u00f5es magn\u00e9ticas em boratos de ferro que s\u00e3o simultaneamente […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13,5,12,1,6],"tags":[],"class_list":["post-441","post","type-post","status-publish","format-standard","hentry","category-eletronica","category-geral","category-hardware","category-uncategorized","category-utilidade-publica","entry"],"_links":{"self":[{"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/posts\/441","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/comments?post=441"}],"version-history":[{"count":1,"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/posts\/441\/revisions"}],"predecessor-version":[{"id":447,"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/posts\/441\/revisions\/447"}],"wp:attachment":[{"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/media?parent=441"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/categories?post=441"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bit7.com.br\/main\/wp-json\/wp\/v2\/tags?post=441"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}