Combining High Thermal Stability of MnNi Antiferromagnets With High-Performance MgO-TMR Sensors Through Texture Engineering With Ion Beam Assisted Deposition

Tunneling magnetoresistive (TMR) sensors with enhancedthermal resilience are being pursued for harsh environmentapplications. In this letter, we explore MnNi as a possible candidatefor exchange bias in TMR sensor multilayers. We use ion beamassisted deposition for MnNi layer growth. A significant emergence ofexchange bias field of mu 0Hex=110 mT was obtained in MnNi/CoFebilayers against the ion beam deposited counterpart. In addition, wedemonstrate for the first time in literature the compatibility with state-of-the-art sensor multilayers comprising syntheticantiferromagnets and MgO tunnel barriers. The optimized device shows a tunneling magnetoresistance ratio of 130%atRT and a 30%at 300 degrees C corresponding to sensitivities of 17.0 and 9.5%/mT with well-defined parallel/antiparallel plateausin the full-temperature operation window.