Modulation of magnetic and multiferroic properties by chemical substitution in Fe₂(MoO₄)₃
Ajay Tiwari1*, D. Chandrasekhar Kakarla1, C. E. Lu1, G. D. Dwivedi2, Sreeparvathy P. C1,3, Chia-Hsiu Hsu1,3, F. C. Chuang1,3, Nidhi Puri4, Y.-J. Hu4, J.-Y. Lin4, Suganya Murali5, R. Sankar5, Aprajita Joshi6, Surajit Saha6, C. Dhanasekhar1,7, S. M. Kumawat1, H. Chou1, C. L. Huang8, H. D. Yang1,7
1Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
2Department of Physics, Kalinga University, Nava Raipur, Chhattisgarh, India
3Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
4Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
5Institute of Physics, Academia Sinica, Taipei, Taiwan
6Department of Physics, Indian Institute of Science Education and Research, Bhopal, India
7Center of Crystal Research, National Sun Yat-sen University, Kaohsiung, Taiwan
8Department of Physics, National Cheng-Kung University, Tainan, Taiwan
* Presenter:Ajay Tiwari, email:ajaytiwari@g-mail.nsysu.edu.tw
The magnetic field (H)-induced second magnetic ordering and exotic multiferroic behavior in the L-type ferrimagnet (L-FiM) Fe2(MoO4)3, as reported in Phys. Rev. Mater. 6, 094412 (2022), requires further exploration. In this study, we investigate the possible origin of multiferroic behavior in the Fe2(MoO4)3 system by substituting W for Mo crystallographic site (i.e., Fe2(Mo1-xWxO4)3). This substitution induces isotropic expansion of the crystal unit cell and significantly alters the ground-state magnetic properties, transitioning from L-FiM (x = 0) to AFM (x = 0.6) ordering. A systematic study of magnetization χ (T, H), dielectric constant ε'(T, H) and ferroelectric polarization P (T, H) as a function of W-substitution (x) shows that both TN2 and H-induced P decrease progressively with increasing x, becoming completely suppressed at x = 0.6, thereby establishing the x-T phase diagram. O-K-edge X-ray absorption spectroscopy suggests that p-d orbital hybridization plays a finite role in modulating the magnetic and multiferroic ground states upon W-substitution. Density functional theory further supports this finding, highlighting variations in the ionic character of the Mo/W-O bonds. These findings reveal a complex interplay between crystal structure, magnetic, and electric couplings in Fe2(MoO4)3, providing insight into the possible origin of H-induced TN2 and the accompanying ferroelectric P.
Keywords: L-type ferrimagnetic (L-FiM), Multiferroic, ferroelectric polarization, Orbital hybridization, Chemical substitution