Nontrivial Topological States in BaSn5 Superconductor Probed by de Haas–van Alphen Quantum Oscillations

We report the nontrivial topological states in an intrinsic type-Ⅱ superconductor BaSn₅（T_c～4.4 K） probed by measuring the magnetization, specific heat, de Haas–van Alphen（d Hv A） effect, and by performing first-principles calculations. The first-principles calculations reveal a topological nodal ring structure centered at the H point in the k_z = π plane of the Brillouin zone, which could be gapped by spin-orbit coupling（SOC）, yielding relatively small gaps below ...     

钻井泥浆泵活塞表面多场耦合电沉积Ni-TiN纳米镀层研究

采用多场耦合电沉积方法,在钻井泥浆泵活塞表面制备Ni-TiN纳米镀层.利用X射线衍射仪(XRD)、原子力显微镜(AFM)、摩擦磨损试验机对Ni-TiN纳米镀层微观组织结构和耐磨性能进行研究.XRD分析表明,在钻井泥浆泵活塞试样表面存在金属镍晶粒和TiN粒子.当复合镀液中TiN粒子为6g/L时,Ni-TiN纳米镀层中镍晶粒和TiN粒子的平均粒径分别为65.5 nm和38.6 nm.AFM分析表明,当TiN粒子浓度为6g/L时,镀层表面镍晶的平均粒径最小,其均方根表面粗糙度(RMS)为44.077 nm.摩擦磨损实验测试表明,当复合镀液中TiN粒子为6g/L时,Ni-TiN纳米镀层的磨损量和摩擦系数都最小,其最小磨损量和摩擦系数分别为34.7 mg和0.44.     

Any-polar resistive switching behavior in Ti-intercalated Pt/Ti/HfO2/Ti/Pt device

The special any-polar resistive switching mode includes the coexistence and stable conversion between the unipolar and the bipolar resistive switching mode under the same compliance current. In the present work, the any-polar resistive switching mode is demonstrated when thin Ti intercalations are introduced into both sides of Pt/HfO₂/Pt RRAM device. The role of the Ti intercalations contributes to the fulfillment of the any-polar resistive switching working mechanism, which lies in the filament constructed by the oxygen vacancies and the effective storage of the oxygen ion at both sides of the electrode interface.