Galvanomagnetic effects and manipulation of antiferromagnetic interfacial uncompensated magnetic moment in exchange-biased bilayers

In this work, IrMn$_{3}$/insulating-Y$_{3}$Fe$_{5}$O$_{12}$ exchange-biased bilayers are studied. The behavior of the net magnetic moment $\Delta m_{AFM}$ in the antiferromagnet is directly probed by anomalous and planar Hall effects, and anisotropic magnetoresistance. The $\Delta m_{AFM}$ is proved to come from the interfacial uncompensated magnetic moment. We demonstrate that the exchange bias and rotational hysteresis are induced by the irreversible switching of the $\Delta m_{AFM}$. In the training effect, the $\Delta m_{AFM}$ changes continuously. This work highlights the fundamental role of the $\Delta m_{AFM}$ in the exchange bias and facilitates the manipulation of antiferromagnetic spintronic devices.