Magnetic field-induced ferroelectricity in S = 1/2 kagome staircase compound PbCu3TeO7

Abstract

Ni 3 V 2 O 8 is an archetypical multiferroic material with a kagome staircase structure of S = 1 (Ni 2+ ) spins whose complex interplay between spin ordering and ferroelectricity has been studied for more than a decade. Here, we report a new kagome staircase compound PbCu 3 TeO 7 with Cu 2+ (S = 1/2) spins that exhibits two Néel temperatures at T N1 = 36 K and T N2 = 24 K, and a magnetic field (H)-induced electric polarization (P) below T N2 . Pyroelectric and magnetoelectric current measurements in magnetic fields up to 60 T reveal that for H||c of~8.3 T, a spin-flop transition induces a transverse P||a with a magnitude of 15 µC/m 2 below T N2 . Furthermore, for a parallel configuration with P//H//a, two spin-flop transitions occur, the first at~16 T with P//a of 14 µC/m 2 , and the second at~38 T, where P disappears. Monte Carlo simulations based on 12 major exchange interactions uncover that a sinusoidal amplitude modulation of the spins occurs along the b-axis below T N1 and an incommensurate, proper screw-type spin order occurs in the ac-plane below T N2 . The simulation results show that P//a under H//c stems from a spin-flop transition facilitating an ab-plane-type spiral order, while the two successive spin-flop transitions for H//a result in spiral spin orders in the aband bc-planes. Based on the experimental and theoretical results, we establish field-induced magnetic and electric phase diagrams for the two H directions, demonstrating that the distorted kagome staircase structure with competing intra-interlayer interactions and lifted frustration creates a plethora of different noncollinear spin textures of S = 1/2 spins that in turn induce electric polarization.

Single crystal growth and structural, magnetic, and magnetoelectric properties in spin-frustrated bow-tie lattice of α-Cu5O2(SeO3)2Cl2

“…The w versus T curves increased with decreasing temperature and exhibited a broad hump at T SRMO B 97 K; this is characteristic of short-range or low-dimensional magnetic ordering (SRMO) of several low-dimensional magnetic systems. 6,29 Although the crystal structure showed the three-dimensional connection of Cu 2+ spin 1/2 ions, the presence of an anomaly at T SRMO suggested that the predominant magnetic exchange interactions occur at the two-dimensional a-c plane, where Cu2 and Cu3 spins formed distorted bow-tie lattice. The a-c planes were magnetically connected through a weak exchange interaction.…”

“…2 Among multiferroic materials, Cu 2+ S = 1/2 spin-based multiferroics are garnering interest because of their complex magnetic ordering with spin frustration, which triggers various quantum effects. [3][4][5][6][7] Many new physical properties have been discovered in cupric oxides, for example, superconductivity, charge density waves, multiferroicity, and skyrmions properties. 3,4,[6][7][8][9][10] When Cu 2+ spin 1/2 ions appear in a dimensionally restricted crystallographic lattice, they exhibit novel quantum magnetic landscapes.…”

“…[3][4][5][6][7] Many new physical properties have been discovered in cupric oxides, for example, superconductivity, charge density waves, multiferroicity, and skyrmions properties. 3,4,[6][7][8][9][10] When Cu 2+ spin 1/2 ions appear in a dimensionally restricted crystallographic lattice, they exhibit novel quantum magnetic landscapes. [11][12][13] Lowdimension lattices consist either of quasi-two-dimensional (2D) layers in the form of Kagome ´, pyrochlore, square, triangle, and honeycomb or quasi-one-dimensional spin-chains, spin-dimers, and spin-ladders are hosts for various interesting quantum phenomena, including the Bose-Einstein condensation, spinglass state, spin-Peierls transition, quantum spin-liquid state, and multiferroicity.…”

Functional Oxides for Photoneuromorphic Engineering: Toward a Solar Brain

“…Thus, the population structure can be captured by looking at the pairwise interactions between neurons. Many functional oxide properties (ferroelectricity in particular) depends precisely either in nanoscale correlation and atomic collective behavior which may also be induced by/to adjacent materials and interfaces [889] , [890] , [891] , [892] , [893] . In a Hebbian view [894] , synaptic efficacy arises from a presynaptic cell's repeated and persistent stimulation of a postsynaptic cell.…”

Spin-Phonon Resonances in Nearly Polar Metals with Spin-Orbit Coupling

“…The resulting coupling between spin and polar degrees of freedom raises intriguing parallels with insulating multiferroics. Here magnetic field-induced polarization 21 , polarization-switching 22 and ferroelectricity 23 has been observed, offering promise for the development of magnetically recorded ferroelectric memories. 24 Analogously in these Rashba-type polar metals, the coexistence of magnetic and polar orders, could lead to novel spintronics functionalities.…”