Structure and magnetic properties of CoFe/MnN films with Ta underlayer and MnN/CoFe films with Ta toplayer through annealing at various temperatures (T_ann = 300–450 °C) and then field cooling to room temperature at 1.5 kOe are studied. Different samples annealed at T_ann below 400 °C mainly consist of θ-MnN(002) phase; with increasing T_ann, stress relaxation and grain growth of MnN(002) takes place. Distinct phase composition is found for 4 series of films annealed at higher T_ann. The phase composition of MnN layer in the films with T_ann is related to the escape of N from MnN layer and the compounding of Ta with N. The increase of exchange bias field (H_E) with T_ann is related to the promoted crystallinity and stress relaxation of θ-MnN phase, but the vanish of H_E for the films annealed at higher T_ann is due to the disappearance of θ-MnN phase. In this study, Ta/CoFe/MnN/Ta films annealed at T_ann = 375 °C exhibits the largest H_E = 562 Oe due to the optimization of θ-MnN phase and flatter interface. The results in this work provide useful information to fabricate exchange bias system with θ-MnN as an antiferromagnetic layer.

研究了在不同温度（T _ann  = 300–450°C）下退火，然后在1.5 kOe下现场冷却至室温的带有Ta底层的CoFe / MnN薄膜和带有Ta的MnN / CoFe薄膜的结构和磁性。不同的样品退火在T_安低于400℃主要包括θ-MNN（002）相; 随着T _ann的增加，MnN（002）发生应力松弛和晶粒长大。上不同的相的组合物被发现对4系列膜中的高于或等于该退火_安。具有T _ann的薄膜中MnN层的相组成与N从MnN层中逸出以及Ta与N的混合有关。交换偏压场（H _E）随着T _ann的增加涉及θ-MNN相的结晶促进和应力松弛，但H的清漆_Ë在高于或等于该退火膜_安是由于θ-MNN相的消失。在这项研究中， 由于θ-MnN相的优化和界面平坦，在T _ann  = 375°C下退火的Ta / CoFe / MnN / Ta膜表现出最大的H _E = 562 Oe。这项工作的结果为使用θ-MnN作为反铁磁层制造交换偏压系统提供了有用的信息。