Fe-Pd-X Thin Film-Polymer Composites for Sensor Applications - First-principles evaluation of magneto-crystalline anisotropy and related intrinsic properties of Fe-Pd-X: optimization of alloy composition

用于传感器应用的 Fe-Pd-X 薄膜聚合物复合材料 - Fe-Pd-X 磁晶各向异性和相关固有特性的第一原理评估：合金成分的优化

• 批准号: 28259700
• 负责人: Privatdozent Dr. Manuel Richter
• 金额: --
• 依托单位: Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (IFW) e.V.
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/28259700?language=en
• 关键词: Fe; Pd; Thin; Film; Polymer

This project is part of a collaboration aiming at new magnetic shape memory Fe-Pd-X alloys for sensor applications. Magnetic shape memory alloys (MSMA) have received much attention in recent years. They are of interest for actuator applications due to large magnetically induced strains of up to 10% in Ni2MnGa. However, application of this material is restricted due to low blocking forces. A promising MSMA is the Fe70Pd30 alloy with smaller strains but significantly higher blocking stresses of 10 MPa. Optimization of this alloy by adding third elements is necessary to facilitate its application in sensors. Here, first-principles calculations are envisaged to (i) gain fundamental understanding of the intrinsic properties (spontaneous magnetization, tetragonal distortion, magneto-crystalline anisotropy) of Fe-Pd alloys and (ii) predict the change of intrinsic properties if other elements are added to produce ternary (quaternary) Fe-Pd-X(-Y) systems. While the field-induced strain at low external field and vanishing external stress is proportional to the spontaneous magnetization, the achievable maximum strain and the blocking stress are unavoidably determined by the magneto-crystalline anisotropy energy. Thus, knowledge of both intrinsic properties is necessary to judge the technological applicability of a certain alloy. On the other hand, the magneto-crystalline anisotropy of MSMA is difficult to measure. Thus, first-principles calculations are needed both for the prediction of expected properties and for the understanding of measured data.

该项目是一项合作的一部分，旨在开发用于传感器应用的新型磁性形状记忆 Fe-Pd-X 合金。磁性形状记忆合金（MSMA）近年来受到广泛关注。由于 Ni2MnGa 中高达 10% 的大磁感应应变，它们在执行器应用中很受关注。然而，由于阻挡力低，该材料的应用受到限制。一种很有前途的 MSMA 是 Fe70Pd30 合金，它具有较小的应变，但具有显着更高的 10 MPa 的阻塞应力。通过添加第三元素来优化这种合金对于促进其在传感器中的应用是必要的。在这里，第一性原理计算的目的是（i）获得对 Fe-Pd 合金的固有特性（自发磁化、四方畸变、磁晶各向异性）的基本了解，以及（ii）预测如果添加其他元素以产生三元（四元）Fe-Pd-X(-Y) 系统时固有特性的变化。虽然低外场和消失的外应力下的场感应应变与自发磁化强度成正比，但可实现的最大应变和阻塞应力不可避免地由磁晶各向异性能量决定。因此，了解这两种内在特性对于判断某种合金的技术适用性是必要的。另一方面，MSMA 的磁晶各向异性很难测量。因此，为了预测预期特性和理解测量数据，都需要第一性原理计算。