Non-collinear antiferromagnetism of coupled spins and pseudospins in the double perovskite La2CuIrO6
Kaustuv Manna, R. Sarkar, S. Fuchs, Y. A. Onykiienko, A. K. Bera, G. Aslan Cansever, S. Kamusella, A. Maljuk, C. G. F. Blum, L. T. Corredor, A. U. B. Wolter, S.… 展开作者
Kaustuv Manna, R. Sarkar, S. Fuchs, Y. A. Onykiienko, A. K. Bera, G. Aslan Cansever, S. Kamusella, A. Maljuk, C. G. F. Blum, L. T. Corredor, A. U. B. Wolter, S. M. Yusuf, M. Frontzek, L. Keller, M. Iakovleva, E. Vavilova, H. -J. Grafe, V. Kataev, H. -H. Klauss, D. S. Inosov, S. Wurmehl, B. Büchner
We report the structural, magnetic and thermodynamic properties of the double perovskite compound La2CuIrO6 from X-ray, neutron diffraction, neutron depolarization, dc magnetization, ac susceptibility, specific heat, muon-spin-relaxation (uSR), electron-spin-resonance (ESR) and nuclear magnetic resonance (NMR) measurements. Below ~113 K, short-range spin-spin correlations occur within the Cu2+ sublattice. With decreasing temperature, the Ir4+ sublattice progressively involves in the correlation process. Below T = 74 K, the magnetic sublattices of Cu (spin s = 1/2) and Ir (pseudospin j = 1/2) in La2CuIrO6 are strongly coupled and exhibit an antiferromagnetic phase transition into a non-collinear magnetic structure accompanied by a small uncompensated transverse moment. A weak anomaly in ac-susceptibility as well as in the NMR and μSR spin lattice relaxation rates at 54 K is interpreted as a cooperative ordering of the transverse moments which is influenced by the strong spin-orbit coupled 5d ion Ir4+. We argue that the rich magnetic behaviour observed in La2CuIrO6 is related to complex magnetic interactions between the strongly correlated spin-only 3d ions with the strongly spin-orbit coupled 5d transition ions where a combination of the spin-orbit coupling and the low-symmetry of the crystal lattice plays a special role for the spin structure in the magnetically ordered state.
Three-dimensional Stacking of Canted Antiferromagnetism and Pseudospin Current in Undoped Sr$_2$IrO$_4$: Symmetry Analysis and Microscopic Model Realization
Temperature induced phase transition from cycloidal to collinear antiferromagnetism in multiferroic Bi$_{0.9}$Sm$_{0.1}$FeO$_3$ driven by $f$-$d$ induced magnetic anisotropy
Collinear-to-Spiral Spin Transformation without Changing Modulation Wavelength upon Ferroelectric Transition in Tb1-xDyxMnO3
用X射线衍射和中子衍射研究了铁电居里温度T_C附近的磁电化合物Tb_（1-x）Dy_xMnO_3的晶格调制和磁结构。对于0.50< x < 0.68的化合物，通过T_C观察到温度无关的调制矢量。这表明，铁电性与极化（P）沿c轴的RMnO 3系列不能归因于这样的ininadenate相称的过渡的反铁磁秩序，如先前预期的。X=0.59的单晶的中子衍射研究表明，FE转变伴随着Mn自旋取向从正弦（共线）反铁磁性到横向螺旋结构的转变。在T_C以下观察到的螺旋结构预期沿c轴产生P，并具有“逆”Dzialoshinski-Moriya相互作用，这与观察一致。
Robust spin splitting and fermiology in the layered altermagnet CoNb4Se8
Technische Universität Berlin（柏林工业大学）；Fritz Haber Institut der Max Planck Gesellshaft（马克斯·普朗格社会弗里茨·哈伯研究所）；Synchrotron SOLEIL（SOLEIL同步辐射中心）；Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies（巴黎-萨克雷大学，法国国家科学研究中心，纳米科学和纳米技术中心）；Diamond Light Source Ltd（钻石光源有限公司）；Université Paris-Saclay, UVSQ, CNRS, GEMaC（巴黎-萨克雷大学，凡尔赛大学，法国国家科学研究中心，GEMaC）；Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University（奥胡斯大学物理与天文系，跨学科纳米科学中心）；CNR-Istituto Officina dei Materiali (IOM), Unità di Trieste（意大利国家研究委员会材料研究所（IOM），的里雅斯特分部）；Dipartimento di Fisica, Università degli Studi di Trieste（的里雅斯特大学物理系）；Elettra - Sincrotrone Trieste S.C.p.A.（Elettra - 的里雅斯特同步辐射股份有限公司）；CNR-SPIN, c/o Universitá di Salerno（意大利国家研究委员会自旋物理学研究所，设于萨莱诺大学）
Nematic fluctuations in the non-superconducting iron pnictide BaFe$_{1.9-x}$Ni$_{0.1}$Cr$_{x}$As$_{2}$
铁基超导体中电子相变的主要驱动力仍在争论中。利用电子输运、角分辨光电子能谱（ARPES）和非弹性中子散射（INS）测量方法，对非超导铁磷属元素化物BaFe $_{1.9-x}$ Ni $_{0.1}$ Cr $_{x}$ As $_{2}$体系的电子涨落进行了全面的研究.以前的中子衍射和输运测量表明，共线反铁磁性持续到$x=0.8$，具有类似的Néel温度$T_N$和结构转变温度$T_s$约32 K，但电荷载流子在$x=$ 0.5附近从电子型变为空穴型。在这项研究中，我们发现，在平面电阻率各向异性也高度依赖于铬掺杂和电荷载流子的类型。虽然ARPES测量表明，对于$x=0.05$和$x=0.5$化合物，在$T_s$附近可能存在较弱的轨道各向异性开始，但INS实验清楚地揭示了低能自旋激发各向异性的不同开始温度，这可能与自旋向列性的能量标度有关。这些结果表明，铁原子上的局域自旋和费米面上的巡游电子之间的相互作用对铁磷属元素化物的自旋涨落是至关重要的，其中轨道自由度的行为可能与自旋自由度不同，输运性质与自旋动力学密切相关.
