Unravelling the effect of SrTiO3 antiferrodistortive phase transition on the magnetic properties of La0.7Sr0.3MnO3 thin films
D. A. Mota, Y. Romaguera Barcelay, A. M. R. Senos, C. M. Fernandes, P. B. Tavares, I. T. Gomes, P. Sá, L. Fernandes, B. G. Almeida, F. Figueiras, P. Mirzadeh Va… 展开作者
D. A. Mota, Y. Romaguera Barcelay, A. M. R. Senos, C. M. Fernandes, P. B. Tavares, I. T. Gomes, P. Sá, L. Fernandes, B. G. Almeida, F. Figueiras, P. Mirzadeh Vaghefi, V. S. Amaral, A. Almeida, J. Pérez de la Cruz, J. Agostinho Moreira
Epitaxial La0.7Sr0.3MnO3 (LSMO) thin films, with different thickness ranging from 20 nm up to 330 nm, were deposited on (100)-oriented strontium titanate (STO) substrates by pulsed laser deposition, and their structure and morphology characterized at room temperature. Magnetic and electric transport properties of the as-processed thin films reveal an abnormal behavior in the temperature dependent magnetization M(T) below the antiferrodistortive STO phase transition (TSTO) and also an anomaly in the magnetoresistance and electrical resistivity close to the same temperature. Up to 100 nm LSMO thin films, an in-excess magnetization and pronounced changes in the coercivity are evidenced, achieved through the interface-mediated magnetoelastic coupling with antiferrodistortive domain wall movement occurring below TSTO. Contrarily, for thicker LSMO thin films, above 100 nm, an in-defect magnetization is observed. This reversed behavior can be understood within the emergence in the upper layer of the film, observed by high resolution transmission electron microscopy, of a branched structure needed to relax elastic energy stored in the film which leads to randomly oriented magnetic domain reconstructions. For enough high-applied magnetic fields, as thermodynamic equilibrium is reached, a fully suppression of the anomalous magnetization occurs, wherein the temperature dependence of the magnetization starts to follow the expected Brillouin behavior.
Unravelling the Role of Stacking Disorder on the Optoelectronic Properties of Zn3P2
Catalan Institute of Nanoscience and Nanotechnology（加泰罗尼亚纳米科学技术研究所）；Ruhr University Bochum（波鸿鲁尔大学）；Friedrich-Schiller-Universität Jena（耶拿弗里德里希·席勒大学）；Lund University（隆德大学）；Ecole Polytechnique Fédérale de Lausanne（洛桑联邦理工学院）；Catania University（卡塔尼亚大学）
Anomalous Transport in High-Mobility Superconducting SrTiO$_3$ Thin Films
研究半导体中输运的细微影响需要具有低缺陷密度的高质量外延结构。采用混合分子束外延（MBE）技术，在3 × 10 $^{17}$ cm $^{-3}$的低载流子密度下，获得了低温迁移率超过42，000 cm $^2$ V $^{-1}$ s $^{-1}$的SrTiO $_3$薄膜.在第二个Lifshitz过渡（LT）的第三个频带被占用，揭示占主导地位的带内散射的剩余电阻率的突然和急剧下降的超导转变温度的增强。这些薄膜进一步揭示了作为反铁磁畸变（AFD）过渡和霍尔散射因子的温度依赖性的结果在霍尔载流子密度的异常行为。使用混合MBE生长，唯象建模，温度相关的传输测量，和扫描超导量子干涉器件成像，我们提供了重要的洞察到的重要作用，带内与带间散射和AFD畴壁的正常状态和超导性能的SrTiO $_3$。
