相关论文: Improper multiferroicity and colossal dielectric c…

Magnetic and dielectric properties on a polycrystalline La0.7Bi0.3CrO3 have been investigated. A canted antiferromagnetic (CAF) phase transition giving weak ferromagnetism at TN = 230K has been observed. M-H at 10K shows non-saturating…

The geometrically frustrated magnet Ni3V2O8 undergoes a series of competing magnetic ordering at low temperatures. Most importantly, one of the incommensurate phases has been reported to develop a ferroelectric correlation caused by spin…

Multilayered cuprates possess not only the highest superconducting temperature transition but also offer a unique platform to study disorder-free CuO$_2$ planes and the interplay between competing orders with superconductivity. Here, we…

A new multiferroic material, CuBr2, is reported for the first time. CuBr2 has not only a high transition temperature (close to liquid nitrogen temperature) but also low dielectric loss and strong magnetoelectric coupling. These findings…

We investigate magnetoelectric coupling and low-energy magnetic excitations in multiferroic $\alpha$-Cu$_2$V$_2$O$_7$ by detailed thermal expansion, magnetostriction, specific heat and magnetization measurements in magnetic fields up to…

We report the low-temperature coexistence in NdFe3(BO3)4 of an incommensurate magnetic phase with a strained commensurate magnetic phase that is primarily at the surface of the crystal. Increasing the temperature or magnetic field decreases…

A remarkably high saturation magnetization of ~0.4mu_B/Fe along with room temperature ferromagnetic hysteresis loop has been observed in nanoscale (4-40 nm) multiferroic BiFeO_3 which in bulk form exhibits weak magnetization (~0.02mu_B/Fe)…

Recently, the perovskite BiCoO$_3$ has been shown experimentally to be isostructural with PbTiO$_3$, while simultaneously the $d^6$ Co$^{3+}$ ion has a high spin ground state with $C$-type antiferromagnetic ordering. Using hybrid density…

We report magnetic and magnetoelectric studies on BiFeO3 and divalent cation (A) suvtitute Bi0.7A0.3FeO3 (A = Sr,Ba, and Sr0.5Ba0.5). It is shown that the rapid increase of magnetization at the Neel temperature (TN = 642 K) is suppressed in…

The out-of-plane dielectric constant of the parent insulator of the high-temperature superconductor Bi_2Sr_2(Dy,Er)Cu_2O_8 was measured and analysed from 80 to 300 K in the frequency range of 10^6-10^9 Hz. All the samples were found to show…

Multiferroic materials combine multiple ferroic orders that may enable cross-functionalities, e.g. control of one ferroic order by the field conjugate to the other one. BaCoSiO$_4$, a recently proposed multiferroic combines multiple unit…

We report on the formation of topological defects emerging from the cycloidal antiferromagnetic order at the surface of bulk BiFeO$_3$ crystals. Combining reciprocal and real-space magnetic imaging techniques, we first observe, in a single…

The polar magnet CaBaCo$_{4}$O$_{7}$ is known to exhibit the largest magnetic-field-driven electric polarization change ($\Delta P$) associated with an antiferromagnetic (AFM)-ferrimagnetic (FIM) transition in a narrow temperature range…

The low-frequency dielectric response of hole-doped insulators La_{2}Cu_{1-x}Li_{x}O_{4} and La_{2-x}Sr_{x}NiO_{4} shows a large dielectric constant \epsilon ^{'} at high temperature and a step-like drop by a factor of 100 at a…

We observe the large enhancement in the dielectric response near the percolation threshold in a composite nanoparticle system consisting of metallic RuO$_2$ grains embedded into dielectric CaCu$_3$Ti$_4$O$_1$$_2$ (CCTO) matrix and annealed…

From an experimental point of view, room temperature ferroelectricity in BiFeO3 is raising many questions. Electric measurements made a long time ago on solid-solutions of BiFeO3 with Pb(Ti,Zr)O3 indicate that a spontaneous electric…

We have measured the magnetization and specific heat of multiferroic CoCr2O4 in magnetic fields up to 14 T. The high-field magnetization measurements indicate a new phase transition at T* = 5 - 6 K. The phase between T* and the lock-in…

Hexagonal rare-earth ferrite RFeO$_3$ family represents a unique class of multiferroics exhibiting weak ferromagnetism, and a strong coupling between magnetism and structural trimerization is predicted. However, the hexagonal structure for…

Tetragonal distorted spinel of CuMn2-xTixO4 (x = 0, 0.25 and 0.50) was prepared by solid state reaction method followed by neutron diffraction, FTIR spectroscopy, dielectric spectroscopy and magnetization measurements. The neutron…

SrEr$_2$O$_4$ has been characterised by low-temperature powder neutron diffraction, as well as single crystal specific heat and magnetisation measurements. Magnetisation measurements show that the magnetic system is highly anisotropic at…