Bruchmann-Bamberg Vitaly, Weimer Isabell, Roddatis Vladimir, Ross Ulrich, Schüler Leonard, Stroh Karen P, Moshnyaga Vasily
Erstes Physikalisches Institut, Georg-August-University Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany.
Nanomaterials (Basel). 2023 Nov 3;13(21):2897. doi: 10.3390/nano13212897.
Superlattices (SLs) comprising layers of a soft ferromagnetic metal LaSrMnO (LSMO) with in-plane (IP) magnetic easy axis and a hard ferromagnetic insulator LaMnCoO (LMCO, out-of-plane anisotropy) were grown on SrTiO (100)(STO) substrates by a metalorganic aerosol deposition technique. Exchange spring magnetic (ESM) behavior between LSMO and LMCO, manifested by a spin reorientation transition of the LSMO layers towards perpendicular magnetic anisotropy below = 260 K, was observed. Further, 3ω measurements of the [(LMCO)/(LSMO)]/STO(100) superlattices revealed extremely low values of the cross-plane thermal conductivity (300 K) = 0.32 WmK. Additionally, the thermal conductivity shows a peculiar dependence on the applied IP magnetic field, either decreasing or increasing in accordance with the magnetic disorder induced by ESM. Furthermore, both positive and negative magnetoresistance were observed in the SL in the respective temperature regions due to the formation of 90°-Néel domain walls within the ESM, when applying IP magnetic fields. The results are discussed in the framework of electronic contribution to thermal conductivity originating from the LSMO layers.
通过金属有机气溶胶沉积技术，在SrTiO(100)(STO)衬底上生长了由具有面内(IP)易磁化轴的软铁磁金属LaSrMnO(LSMO)层和硬铁磁绝缘体LaMnCoO(LMCO，面外各向异性)层组成的超晶格(SLs)。观察到LSMO和LMCO之间的交换弹簧磁(ESM)行为，表现为LSMO层在低于 = 260 K时向垂直磁各向异性的自旋重取向转变。此外，[(LMCO)/(LSMO)]/STO(100)超晶格的3ω测量显示，其面内热导率极低(300 K时 = 0.32 WmK)。此外，热导率对施加的IP磁场表现出特殊的依赖性，根据ESM引起的磁无序而降低或增加。此外，当施加IP磁场时，由于在ESM内形成90°-奈尔畴壁，在相应温度区域的SL中观察到了正磁阻和负磁阻。在源自LSMO层的热导率的电子贡献框架内讨论了这些结果。
