SIUC Physics Seminar
School of Physics and Applied Physics, Southern Illinois University--Carbondale
2025 February 21 Friday 4:00 PM:
Physics Seminar in Neckers 440
Title: Effects of Partial Isoelectronic Substitution (In for Ga) on Phase Transitions, Magnetic Properties and Magnetocaloric Effect in Mn60Ga20C20 Alloys Fabricated by Ball Milling Technique
Speaker: Abhiyan Oli
Affiliation: Southern Illinois University--Carbondale
Abstract:
In this study, we explore the impact of partial isoelectronic substitution
(In for Ga) on the magnetic properties and magnetocaloric effect of the
material Mn60Ga20-xInxC20
(x= 1, 2, 3, 4, 5). Since this system involves isoelectronic substitution,
the concentration of conduction electrons remains unchanged. Therefore,
the observed changes in properties can be related to the variations in the
crystal cell volume. Our investigations show that the alloys crystallized
in an anti-perovskite cubic structure within space group Pm-3m, with a lattice
constant of 3.90 Å. We observed that as the In-concentration increases,
the Curie temperature (TC) rises, while the TM decreases
reaching values of 272 K, and 149 K, respectively for x =5. Thus, the expansion
of cell volume results in an increase in the interval of the temperature
stability of high-temperature austenitic (AP) phase and ferromagnetic
interaction in AP. The magnetization curves M(H) obtained at 10 K with
applied fields (H > 10 kOe) exhibit ferromagnetic-like behavior.
Near TC, the alloy with a concentration of x = 4, showed the
highest magnetic entropy change
(|ΔSM| = 3.1 JKg-1K-1) and the
highest Relative Cooling Power (RCP = 245 JKg-1) induced by
a magnetic field change of ΔH = 50 kOe. Additionally, in the vicinity
of transition temperature, TM, the compound (x=1) reveals
a high magnetic entropy change
|ΔSM| = 5 JKg-1K-1 and the
compound with x=5 shows the highest RCP = 217 JKg-1.
Last updated on
by K V Shajesh
(kvshajesh@gmail.com).