Unique Multiferroics with Tunable Ferroelastic Transition in Antiferromagnet Mn2V2O7

Multiferroics have received considerable interest over the last decade due to the fascinating fundamental phenomena and potential use in various applications, such as low-power electronics and spintronics. Among those, investigations have focused on the coexistence of ferroelectric and ferromagnetic mate-rials. Here, we report the rare case that the para-to ferroelastic ordering transition in antiferromagnet Mn2V2O7 occurred at T-S = 260-280 K, verified by temperature-dependent magnetization measurements, dielectric, differential scanning calorimetry, and macroscopic strain-stress hysteresis loops. Furthermore, this transition was accompanied by a structural transition from the high-temperature C2/m monoclinic phase (beta-phase) to a low-temperature P (1) over bar triclinic phase (alpha-phase), as identified by temperature-dependent X-ray diffraction. Consequently, T-S can be successfully increased by Co-and Ni-doping and decreased by Ca-doping. Thus, the phase diagram was established for the structural stability of (Mn(1-x)A(x))(2)V2O7 (A = Co, Ni, and Ca). In addition, the physical and chemical pressure effects were applied on (Mn(1-x)C(a)x)(2)V2O7 to correlate the ferroelastic (TS) and antiferromagnetic (TN) orderings. Consequently, the magnetoelastic coupling was revealed, and a unique multiferroic material (Mn2V2O7) with a fer-roelastic and antiferromagnetic ordering was obtained. (C) 2022 Elsevier Ltd. All rights reserved.