相关论文: Tuning of Quantum Paraelectricity of M-type Hexafe…
The ground state of BaFe12O19 (BFO) is controversial as three different quantum states, namely quantum paraelectric, frustrated antiferroelectric and quantum electric dipole liquid (QEDL), have been proposed. We have investigated the…
The intrinsic ferroelectricity and related dielectric properties of M-type Barium Hexaferrite (BaFe12O19) with excellent magnetic performance are reported in this paper. A classic electric polarization (P-E) hysteresis loop with full…
Geometric frustrations and quantum mechanical fluctuations may prohibit the formation of long-range ordering even at the lowest temperature, and therefore liquid-like ground states could be expected. A good example is the quantum spin…
On the basis of first-principles calculations we show that the M-type hexaferrite BaFe12O19 exhibits frustrated antiferroelectricity associated with its trigonal bipyramidal Fe3+ sites. The ferroelectric (FE) state of BaFe12O19, reachable…
Phase transition between ferroelectricity and quantum paraelectricity via non-thermal tuning parameters can lead to quantum critical behavior and associated emergent phenomena. Ferroelectric quantum critical systems are, however, rare…
We prepared Mn- and Ti mono-doped and co-doped BaFe12O19 hexaferrites via solid-state reaction. Mn ions preferentially occupy the 4f2 and 2b sites, while Ti ions mainly substitute the Fe3+ ions at 4f1 and 12k sites as revealed by the Raman…
BaFe12O19 is a popular M-type hexaferrite with T(Neel) = 720 K of enormous commercial value (3 billion dollars/year). It exhibits an incipient ferroelectric phase transition (in violation of the Spaldin-Hill rule) extrapolated to lie at 6.0…
The temperature dependence of static dielectric susceptibility of a system with strongly coupled fluctuating dipoles is calculated within a self consistent mean fluctuation field approximation. Results are qualitatively in good agreement…
High quality single crystals of BaFe$_{12}$O$_{19}$ were grown using the floating zone technique in flowing oxygen pressurized to 100 atm. Single crystal neutron diffraction was used to determine the nuclear and magnetic structure of…
Materials tuned to the neighbourhood of a zero temperature phase transition often show the emergence of novel quantum phenomena. Much of the effort to study these new effects, like the breakdown of the conventional Fermi-liquid theory of…
Evidence for a re-entrant quantum paraelectric (QPE) state preceded by a dipole glass (DG) phase with a non-classical exponent in the quantum critical regime of SrFe12O19 is presented. It is shown that the DG transition is accompanied with…
The dipole ordering in Sn(Pb)$_2$P$_2$S(Se)$_6$ materials may be tuned by chemical substitution realizing a ferroelectric quantum phase transition and quantum glassy or relaxor type phenomena on different parts of the phase diagram. The…
Entanglement of two different quantum orders is of an interest of the modern condensed matter physics. One of the examples is the dynamical multiferroicity, where fluctuations of electric dipoles lead to magnetization. We investigate this…
The effect of ferroelectric fluctuations on the temperature dependent dielectric constant of SrTiO$_3\,$(STO) has been long studied. Those fluctuations have been shown in recent years to be quantum critical and STO demonstrated to form the…
We present a microscopic model of the quantum paraelectric-ferroelectric phase transition with a focus on the influence of coupled fluctuating phonon modes. These may drive the continuous phase transition first order through a metaelectric…
Quantum criticality has been invoked as being essential to the understanding of a wide range of exotic electronic behavior, including heavy Fermion and unconventional superconductivity, but conclusive evidence of quantum critical…
A fragile ordered state can be easily tuned by various external parameters. When the ordered state is suppressed to zero temperature, a quantum phase transition occurs, which is often marked by the appearance of unconventional…
Based on the earlier published theory (\textit{Nature Mat}. \textbf{18}, 223--228 (2019)), a comprehensive experimental investigation of multiferroic quantum critical behavior of (Eu,Ba,Sr)TiO$_3$ polycrystalline and single crystal samples…
Quantum matter hosts a large variety of phases, some coexisting, some competing; when two or more orders occur together, they are often entangled and cannot be separated. Dynamical multiferroicity, where fluctuations of electric dipoles…
A realistic theory of the quantum paraelectric - ferroelectric transition is presented, involving parameters determined from band calculations and a renormalization group treatment of critical fluctuations. The effects of reduced…