Thermomagnetic (TM) generators based on Heusler alloy films have the potential to recover waste heat below 200°C at small temperature differences . Progress in the development of materials that exhibit large abrupt changes in ferromagnetic ordering and in film engineering enable efficient thermomagnetic generation via resonant self-actuation of freely movable film-based devices. Yet, power levels of individual devices are low, and upscaling becomes a key issue of material development and engineering. Here, we address the key question of how film thickness and device footprint affect power and efficiency. We investigate the scaling performance of heat intake, heat dissipation, and resulting local temperature changes. Based on this understanding, the electrical power per footprint could be increased by a factor of 3.4. Maximum values of electrical power per footprint are 50 μW/cm² at a temperature change of only 3°C, which marks an important milestone in the upscaling of Heusler alloy film-based TM generators.

基于Heusler合金薄膜的热磁（TM）发生器具有在小温差下回收200°C以下废热的潜力。在铁磁有序和薄膜工程中表现出巨大突变的材料的开发进展，通过可自由移动的基于薄膜的器件的共振自致动，实现了有效的热磁产生。然而，单个设备的功率水平很低，并且升级成为材料开发和工程设计的关键问题。在这里，我们解决了关键问题，即薄膜厚度和器件占位面积如何影响功率和效率。我们研究了热量吸收，散热和由此引起的局部温度变化的缩放性能。基于此理解，每足迹的电功率可以增加3.4倍。^图2的温度变化仅为3°C，这标志着基于Heusler合金薄膜的TM发生器升级的重要里程碑。