Proloy T. Das | Searcharxiv

arXiv2026

Piezomagnetic Switching of Nonvolatile Antiferromagnetic States

Prospective spintronic memory and logic devices will benefit from the negligible stray field and ultrafast magnetic dynamics inherent to antiferromagnets [1]. However, realizing isothermal, nonvolatile, and deterministic switching of antiferromagnetic states remains a key challenge [2, 3]. Here, we propose a piezomagnetic writing scheme in triangular Mn3Ir-based memory cells, with readout achieved via the exchange bias effect. Our approach enables deterministic and nonvolatile switching of the antiferromagnetic states, which exhibit exceptional robustness against external perturbations. The switching mechanism is ascribed to piezomagnetic effect of Mn3Ir combined with the interfacial Dzyaloshinskii-Moriya interaction at the antiferromagnet-ferromagnet interface. This scheme overcomes the speed limitations imposed by conventional isothermal methods based on isothermal crystallization mechanism [4]. Our findings highlight the potential of piezomagnetic effects in designing advanced spintronic devices, providing an efficient pathway for manipulating antiferromagnetic states and developing energy-efficient memory technology.

cond-mat.mtrl-sci↗

arXiv2014

Influence of La and Mn vacancies on the electronic and magnetic properties of LaMnO$_{3}$ thin films grown by pulsed laser deposition

With pulsed laser deposition we have grown c-axis oriented thin films of the nominal composition LaMnO$_{3}$ (LMO) on LSAT(001) substrates. We find that, depending on the oxygen background pressure during growth, the LMO films contain sizeable amounts of La and/or Mn vacancies that strongly influence their electronic and magnetic properties. Specifically, we show that the Mn/La ratio can be systematically varied from 0.92 at 0.11 mbar to 1.09 at 0.30 mbar of oxygen. These cationic vacancies lead to markedly different disorder effects that become most pronounced once the samples are fully oxygenated and thus strongly hole doped. All as-grown and thus slightly oxygen deficient LMO films are ferromagnetic insulators with saturation moments in excess of 2.5 μ$_{B}$ per Mn ion, their transport and optical properties that can be understood in terms of trapped ferromagnetic polarons. Upon oxygen annealing, the most La-deficient films develop a metallic response with an even larger ferromagnetic saturation moment of 3.8 μ$_{B}$ per Mn ion. In contrast, in the oxygenated Mn-deficient films the ferromagnetic order is almost completely suppressed to less than 0.5 μ$_{B}$ per Mn ion and the transport remains insulator-like. We compare our results with the ones that were previously obtained on bulk samples and present an interpretation in terms of the much stronger disorder potential of the Mn vacancies as compared to the La vacancies. We also discuss the implications for the growth of LMO thin films with well-defined physical properties that, for example, are a prerequisite for the study of interface effects in multilayers.

cond-mat.str-el↗