Metamagnetic phase transitions in perovskite manganites

Study of disorder effects in La substituted Ca2FeMoO6 ferrimagnet using magnetic and transport measurements

“…They explained the results in terms of decreasing site ordering of Fe 3+ and Mo 5+ ions (i.e., increasing ASD) in Sr 2−x La x FeMoO 6 . Viewing a rich variety of physical properties of La doped perovskite compounds A 1−x La x BO 3 (A: Ca, Sr, Ba; B: Mn) [14][15][16], further experimental works are needed to study the effects of La doping in different double perovskite structure. However, La and other non-magnetic substitutions have been performed mainly on Sr 2 FeMoO 6 double perovskite.…”

Avalanche-like metamagnetic transition in (LaNd)CaMnO manganites

“…The most striking phenomena are the colossal magnetoresistance, charge and orbital ordered states, and the coexistence at different length scales of ferromagnetic (FM) metallic and charge ordered antiferromagnetic (CO-AFM) insulating domains. The latter, known as phase separation, is currently viewed as an intrinsic feature of several strongly correlated electron systems [2], such as superconductors [3], multi-ferroics [4], and magnetocaloric materials [5].Intrinsic disorder and the coexistence of energetically near degenerate phases are key factors to understand this effect [2,6].Metamagnetic transitions, observed in measurements of isothermal magnetization versus magnetic field, M vs. H, are common in manganites [7,8]. The origin of these effects are caused by the field induced transformation of the metastable CO-AFM state at low fields to a homogeneous ferromagnet at high fields.…”

Metamagnetic phase transitions induced by static and pulsed fields in (Sm0.5Gd0.5)0.55Sr0.45MnO3 ceramics

“…4, at temperatures below 60 K, the shape of the magnetization isotherms M(H) obtained in pulsed magnetic fields almost completely coincides with the magnetization curves measured in static magnetic fields at 4.2 K. The metamagnetic phase transition to an ordered ferromagnetic state occurs in a critical magnetic field equal to H c1 ≅ 25 kOe, which remains constant with an increase in the temperature to 60 K. The stability of the induced ferromagnetic phase at temperatures in the range from 4.2 to 60 K is also indi cated by the temperature dependence of the magnetic susceptibility χ(T) measured during heating of the sample, in which the ferromagnetic phase was induced by a strong magnetic field at a temperature of 18 K. The temperature dependence of the magnetic suscep tibility corresponds to the phase transition from an ordered ferromagnetic state to a disordered paramag netic state with an increase in the temperature to a critical value T c ≈ 48 K. The temperature equal to 60 K corresponds to the complete destruction of the long range ferromagnetic ordering of manganese spins and can be regarded as the boundary of stability of the induced ferromagnetic phase, which substantially exceeds the region of the existence of the metastable antiferromagnetic state in zero magnetic field. It should be noted that the magnetization isotherms measured in the temperature range 4.2-60 K do not contain significant discontinuities that are character istic of the previously studied irreversible metamag netic phase transitions [21][22][23][24][25][26] induced in both the static and pulsed magnetic fields. Therefore, the mechanisms proposed in the aforementioned works for the irreversible stabilization of the magnetic field induced ferromagnetic phase cannot explain the pre sented experimental results.…”