TY - JOUR
T1 - Magnetic field-induced ferroelectricity in S = 1/2 kagome staircase compound PbCu3TeO7
AU - Yoo, Kyongjun
AU - Koteswararao, B.
AU - Kang, Jeonghun
AU - Shahee, Aga
AU - Nam, Woohyun
AU - Balakirev, Fedor F.
AU - Zapf, Vivien S.
AU - Harrison, Neil
AU - Guda, Alexander
AU - Ter-Oganessian, Nikita
AU - Kim, Kee Hoon
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Ni3V2O8 is an archetypical multiferroic material with a kagome staircase structure of S = 1 (Ni2+) 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 PbCu3TeO7 with Cu2+ (S = 1/2) spins that exhibits two Néel temperatures at TN1 = 36 K and TN2 = 24 K, and a magnetic field (H)-induced electric polarization (P) below TN2. 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/m2 below TN2. 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/m2, 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 TN1 and an incommensurate, proper screw-type spin order occurs in the ac-plane below TN2. 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 ab- and 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.
AB - Ni3V2O8 is an archetypical multiferroic material with a kagome staircase structure of S = 1 (Ni2+) 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 PbCu3TeO7 with Cu2+ (S = 1/2) spins that exhibits two Néel temperatures at TN1 = 36 K and TN2 = 24 K, and a magnetic field (H)-induced electric polarization (P) below TN2. 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/m2 below TN2. 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/m2, 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 TN1 and an incommensurate, proper screw-type spin order occurs in the ac-plane below TN2. 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 ab- and 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.
UR - http://www.scopus.com/inward/record.url?scp=85053312961&partnerID=8YFLogxK
U2 - 10.1038/s41535-018-0117-0
DO - 10.1038/s41535-018-0117-0
M3 - Article
VL - 3
JO - npj Quantum Materials
JF - npj Quantum Materials
IS - 1
M1 - 45
ER -