Ferrimagnets in the vicinity of the magnetic compensation point are of particular interest for spin-torque-based spintronics applications, because they require lower switching currents and thus smaller switching energies. Room-temperature compensation is rather uncommon, but can be obtained by tuning the chemical concentrations of compounds such as ${\mathrm{Co}}_{0.79}{\mathrm{Tb}}_{0.21}$ or ${\mathrm{Co}}_{0.56}{\mathrm{Gd}}_{0.44}$, in order to find the single concentration at which one sublattice compensates the other. Here we study the ferrimagnetic ${\mathrm{Mn}}_{4\text{−}x}{\mathrm{Co}}_x\mathrm{N}$ films, showing that they presumably possess at room temperature not only one but two different Co concentrations at which the magnetic compensation occurs. Using x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements, we show that this startling behavior can be explained by the existence of two nonequivalent sites for the Co, when it is inserted in the antiperovskite structure of epitaxial ${\mathrm{Mn}}_{4\text{−}x}{\mathrm{Co}}_x\mathrm{N}$ films.

中文翻译：

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稀土Mn4-xCoxN亚铁磁膜中两种不同组成比的磁补偿

对于基于自旋转矩的自旋电子应用，磁性补偿点附近的铁氧体特别受关注，因为它们需要较低的开关电流，因此需要较小的开关能量。室温补偿很少见，但可以通过调节化合物的化学浓度来获得，例如${\mathrm{有限公司}}_{0.79}{b}_{0.21}$ 要么 ${\mathrm{有限公司}}_{0.56}{d}_{0.44}$，以便找到一个子晶格补偿另一个子晶格的单一浓度。在这里我们研究亚铁磁性${锰}_{4\text{-}X}{\mathrm{有限公司}}_X\mathrm{ñ}$薄膜，表明它们大概在室温下不仅具有一种而且还具有两种不同的Co浓度，在该浓度下会发生磁补偿。使用X射线吸收光谱法和X射线磁性圆二色性测量法，我们表明，当将Co插入外延的抗钙钛矿结构中时，可以通过Co的两个非等价位点的存在来解释这种惊人的行为。${锰}_{4\text{-}X}{\mathrm{有限公司}}_X\mathrm{ñ}$ 电影。