Soft magnetic materials (SMMs) serve in electrical applications and sustainable energy supply, allowing magnetic flux variation in response to changes in applied magnetic field, at low energy loss¹. The electrification of transport, households and manufacturing leads to an increase in energy consumption owing to hysteresis losses². Therefore, minimizing coercivity, which scales these losses, is crucial³. Yet meeting this target alone is not enough: SMMs in electrical engines must withstand severe mechanical loads; that is, the alloys need high strength and ductility⁴. This is a fundamental design challenge, as most methods that enhance strength introduce stress fields that can pin magnetic domains, thus increasing coercivity and hysteresis losses⁵. Here we introduce an approach to overcome this dilemma. We have designed a Fe–Co–Ni–Ta–Al multicomponent alloy (MCA) with ferromagnetic matrix and paramagnetic coherent nanoparticles (about 91 nm in size and around 55% volume fraction). They impede dislocation motion, enhancing strength and ductility. Their small size, low coherency stress and small magnetostatic energy create an interaction volume below the magnetic domain wall width, leading to minimal domain wall pinning, thus maintaining the soft magnetic properties. The alloy has a tensile strength of 1,336 MPa at 54% tensile elongation, extremely low coercivity of 78 A m⁻¹ (less than 1 Oe), moderate saturation magnetization of 100 A m² kg⁻¹ and high electrical resistivity of 103 μΩ cm.

软磁材料 (SMM) 用于电气应用和可持续能源供应，允许磁通量变化以响应外加磁场的变化，并且能量损失低¹。^{由于滞后损失2}，交通、家庭和制造业的电气化导致能源消耗增加。因此，最大限度地减少可扩大这些损失的矫顽力至关重要³。然而，仅实现这一目标是不够的：电动发动机中的 SMM 必须承受严重的机械负载；也就是说，合金需要高强度和延展性⁴. 这是一个基本的设计挑战，因为大多数增强强度的方法都会引入应力场，这些应力场可以固定磁畴，从而增加矫顽力和磁滞损耗⁵。在这里，我们介绍一种克服这种困境的方法。我们设计了一种 Fe-Co-Ni-Ta-Al 多元合金 (MCA)，它具有铁磁基体和顺磁性相干纳米颗粒（尺寸约为 91 nm，体积分数约为 55%）。它们阻碍位错运动，增强强度和延展性。它们的小尺寸、低相干应力和小静磁能在磁畴壁宽度以下产生相互作用体积，导致畴壁钉扎最小化，从而保持软磁特性。该合金在 54% 的拉伸伸长率下具有 1,336 MPa 的拉伸强度，78 A m 的极低矫顽力^-1（小于 1 Oe），100 A m ²  kg ^-1的中等饱和磁化强度和 103 μΩ cm 的高电阻率。