Magnetocaloric effect of La0.8Sr0.2MnO3 compound under pressure

Abstract

The La0.8Sr0.2MnO3 compound presents a ferromagnetic paramagnetic transition around room temperature to which a reasonably high magnetocaloric effect is associated, turning this material of interest for application in magnetic refrigeration. We synthesized this compound in fiber single crystalline form by the Laser Heated Pedestal Growth method. The sample was characterized by x-ray diffraction and magnetic measurements as a single phase and with the required magnetic properties. We measured the magnetic properties and the magnetocaloric effect under hydrostatic pressure for pressures up to 6 kbar as a function of temperature. Our results indicate that the Curie temperature increases with pressure while the low temperature transition from the orthorhombic to the rhombhoedral structures decreases as pressure increases. This is in close agreement with the literature. Measurement of the magnetocaloric effect at the high temperature transition indicates that the peak of the effect follows the trend of the Curie temperature, but its maximum value remains almost constant as a function of pressure.

Carbon-doping effects on the metamagnetic transition and magnetocaloric effect in MnAsCx

“…There is also a first-order phase transition in MnAs under hydrostatic pressure [8]. When subjected to pressure, similar large MCE was found in Gd 5 Ge 2 Si 2 [9], La 0.8 Sr 0.2 MnO 3 [10] and La(Fe 1 À x Si x ) 13 H y [11] assisted by magnetoelastic interactions. Specifically, bulk MnAs undergoes a magnetic transition from a ferromagnetic (FM) phase to a paramagnetic (PM) phase at T c = 313 K, accompanied by a structural transition from hexagonal NiAs-type to orthorhombic MnP-type [12].…”

Magnetoresistance and structural characterization of electrospun La1−Sr MnO3 nanowire network fabrics with x = 0.2

“…which is higher than that found measuring amorphous LSMO powder of the same composition, T C ≈ 305 K [23]. In (b), the results of MTGA in the temperature range 300 K < T < 470 K are shown with an applied magnetic field of 0.1 T. When the sample changes from the paramagnetic to ferromagnetic state, the experienced magnetic force counteracts the gravity of the sample mass.…”

Study of high‐pressure‐induced phase transition in nanocrystalline perovskite (LaSr)(MnFe)O3by Raman spectroscopy

“…At 9.2 GPa, a single broad peak is observed at 550 cm 1 . The intense peak might be considered as either due to the merging of 3 and 4 or due to the vanishing of 4 with the increment in 3 . Associating the result with Mössbauer and HPXRD measurements, the presence of the nanoparticles along with the single phase composition at this high pressure strongly recommends the former option.…”

“…Although there are reports of temperature-induced structural changes, 2 very few studies have been reported on the high-pressure behavior of these compounds. 3 -5 A continuous decrease in the Jahn-Teller distortion with increase in pressure in LaMnO 3 and La x Sr 2 x MnO 4 has been reported. 6,7 Doping with Fe at Mn site dilutes the Jahn-Teller atoms, giving a series of double-exchange ferromagnets of decreasing transfer carrier concentration.…”