Gallium Iron room temperature Magnetoelectric Oxides

镓铁室温磁电氧化物

• 批准号: 208216925
• 负责人: Professorin Dr. Marjana Lezaic
• 金额: --
• 依托单位: PGI-1 / IAS-1: Quanten-Theorie der Materialien
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/208216925?language=en
• 关键词: Gallium; Iron; room; temperature; Magnetoelectric

Magnetoelectric (ME) materials, presenting a coupling between their magnetic and electric properties, allow the control of the magnetization of a material through an electric field. This opens perspectives towards a new type of non volatile memory with high endurance, low access time and low power consumption: magnetoelectric memories (MERAMs). Unfortunately, materials presenting a ME coupling are scarce. Those presenting this effect at room temperature and having a non zero magnetization, essential for the real development of the applications, are even scarcer.We propose to study the possibilities in terms of magnetoelectricity of a promising but still rather unknown material, especially in thin films: Ga2-xFexO3 (GFO). This material is pyroelectric, ferrimagnetic, and has one of the highest ME couplings observed for a single-phased material. It’s the first material observed to simultaneously present a strong ME coupling and a resulting magnetization. Its Curie temperature is above room temperature (370 K) for x=1.4. The origin of its electric and ME properties is however still unclear. Until recently, no sufficiently high crystalline quality thin films of this material could be made. This de facto annihilated its potential applications in electronic devices.This project proposes to take advantage of the ability recently acquired by one of the partners to deposit high quality GFO thin films. Its goal is to perform a complete theoretical and experimental study of GFO magnetoelectricity. The theoretical part will consist in first principles calculations aiming at determining the origin of the ME effect in GFO, with a view to find ways to increase it. Different dopings of the GFO structure will be considered, guided by the theoretical part. Consistency of the theoretical part will be evaluated a posteriori through comparison of its predictions with the ME effect experimental characterization of pure and doped GFO thin films.

磁电 (ME) 材料具有磁特性和电特性之间的耦合，可以通过电场控制材料的磁化强度。这为具有高耐用性、低访问时间和低功耗的新型非易失性存储器开辟了前景：磁电存储器（MERAM）。不幸的是，展示 ME 耦合的材料很少。那些在室温下呈现这种效应并且具有非零磁化强度的材料甚至更少，这对于真正的应用开发至关重要。我们建议研究一种有前途但仍然相当未知的材料的磁电可能性，特别是在薄膜中：Ga2-xFexO3 (GFO)。这种材料具有热释电、亚铁磁性，是单相材料中观察到的最高 ME 耦合之一。它是第一种被观察到同时呈现强 ME 耦合和由此产生的磁化的材料。当 x=1.4 时，其居里温度高于室温 (370 K)。然而，其电和 ME 特性的起源仍不清楚。直到最近，这种材料还无法制成结晶质量足够高的薄膜。这实际上消除了其在电子设备中的潜在应用。该项目建议利用合作伙伴之一最近获得的能力来沉积高质量的 GFO 薄膜。其目标是对 GFO 磁电进行完整的理论和实验研究。理论部分将包括第一原理计算，旨在确定 GFO 中 ME 效应的起源，以期找到增加它的方法。在理论部分的指导下，将考虑 GFO 结构的不同掺杂。理论部分的一致性将通过将其预测与纯 GFO 薄膜和掺杂 GFO 薄膜的 ME 效应实验表征进行比较来评估。