Magnetoelectric coupling and polarization reversal in 1-D spin chain FePbBiO₄

Ajay Tiwari¹, W. L. Chen¹, C. Dhanasekhar¹, J.-Y. Lin^2,3, C. W. Wang⁴, M. M. C. Chou^1,5, H. D. Yang¹, D Chandrasekhar Kakarla^1*

¹Physics, National Sun Yat-sen University, KAOHSIUNG, Taiwan
²Institute of Physics, National Yang-Ming Chiao Tung University, Hsinchu, Taiwan
³Center for Emergent Functional Matter Science, National Yang-Ming Chiao Tung University, Hsinchu, Taiwan
⁴National Synchrotron Radiation Research Center, Hsinchu, Taiwan
⁵Center of Crystal Research, National Sun Yat-sen University, Kaohsiung, Taiwan

* Presenter:D Chandrasekhar Kakarla, email:chandu@g-mail.nsysu.edu.tw

The type-II multiferroic characteristics on a quasi-one-dimensional spin-chain compound FePbBiO₄) were reported. Two distinct antiferromagnetic (AFM) orderings that occurred at 23K (T_N1) and 12K (T_N2) were verified by magnetization and specific heat measurements. The dielectric anomalies were also shown in the corresponding temperatures. The most striking finding is that no pyrocurrent signal was detected without field; however, magnetic field-induced ferroelectric polarization (P) at T_N1 unexpectedly partially reversed below T_N2 through the temperature and magnetic field-dependent pyrocurrent measurements with applying positive and negative poling electric field. The resultant H-T phase diagram of FePbBiO₄) illustrates the magnetic field-dependent spin ordering-induced polarizations in this type-II multiferroic behavior. The interplay among T, H, spin dynamics, and lattice structures is pivotal and has been qualitatively proposed in the observed multiferroic nature. Nevertheless, the precise underlying mechanisms governing those correlations remain elusive and require further experimental and theoretical exploration.

Keywords: Multiferroic, Ferroelectric polarization, Spin-Chain