Multiferroics materials, which exhibit coupled magnetic and ferroelectric properties, have attracted tremendous research interest because of their potential in constructing next-generation multifunctional devices. The application of single-phase multiferroics is currently limited by their usually small magnetoelectric effects. Here, we report the realization of giant magnetoelectric effects in a Y-type hexaferrite Ba_0.4Sr_1.6Mg₂Fe₁₂O₂₂ single crystal, which exhibits record-breaking direct and converse magnetoelectric coefficients and a large electric-field-reversed magnetization. We have uncovered the origin of the giant magnetoelectric effects by a systematic study in the Ba_2-x Sr _x Mg₂Fe₁₂O₂₂ family with magnetization, ferroelectricity and neutron diffraction measurements. With the transverse spin cone symmetry restricted to be two-fold, the one-step sharp magnetization reversal is realized and giant magnetoelectric coefficients are achieved. Our study reveals that tuning magnetic symmetry is an effective route to enhance the magnetoelectric effects also in multiferroic hexaferrites.Control of the electrical properties of materials by means of magnetic fields or vice versa may facilitate next-generation spintronic devices, but is still limited by their intrinsically weak magnetoelectric effect. Here, the authors report the existence of an enhanced magnetoelectric effect in a Y-type hexaferrite, and reveal its underlining mechanism.

中文翻译：

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通过调节Y型六铁氧体中的自旋锥对称性可实现巨大的磁电效应。

表现出磁性和铁电特性的多铁材料，由于其在构造下一代多功能设备方面的潜力而吸引了巨大的研究兴趣。当前，单相多铁磁的应用受到它们通常较小的磁电效应的限制。在这里，我们报道了在Y型六方铁氧体Ba _0.4 Sr _1.6 Mg ₂ Fe ₁₂ O ₂₂单晶中实现巨大的磁电效应，该单晶表现出创纪录的正，反磁电系数和大的电场反向磁化强度。通过对Ba _2-x Sr的系统研究，我们发现了巨大的磁电效应的起源。_x Mg ₂ Fe ₁₂ O ₂₂系列具有磁化，铁电和中子衍射测量。将横向自旋锥对称性限制为两倍，实现了一步式急剧磁化反转，并获得了巨大的磁电系数。我们的研究表明，调谐磁性对称性也是在多铁性六铁氧体中增强磁电效应的有效途径。通过磁场控制材料的电学特性或反之亦然，这可能有助于下一代自旋电子器件，但仍受其限制固有的弱磁电效应。在这里，作者报告了在Y型六方铁氧体中存在增强的磁电效应，并揭示了其下划线机制。