Magnetic structure and phase formation of magnetocaloric Mn-Fe-P-X compounds

This thesis presents a study of the crystal and magnetic structure, the magnetocaloric effect and related physical properties in Mn-Fe-P-X compounds. The influences of boron addition in (Mn,Fe)2(P,As) compounds have been studied. It is found that boron atoms occupy interstitial sites within the basal plane. First order magnetoelastic phase...

High/low-moment phase transition in hexagonal Mn-Fe-P-Si compounds

Using high-resolution neutron diffraction measurements for Mn-rich hexagonal Mn-Fe-P-Si compounds, we show that the substitution of Mn for Fe on the 3f sites results in a linear decrease of the Fe/Mn(3f) magnetic moments, while the Mn(3g) magnetic moments remain constant. With increasing temperature, the Mn(3g) magnetic moments show almost no...

Enhanced magnetocaloric effects and tunable thermal hysteresis in transition metal pnictides

The effect of Co and Ni substitutions for Fe on the magnetocaloric properties of MnFe(P,Ge) compounds crystallizing in the hexagonal Fe2P type of structure was studied. It was found that, by changing composition, a small thermal hysteresis and a giant magnetocaloric effect can be obtained simultaneously in MnFe(P,Ge) compounds when the magnetic...

From first-order magneto-elastic to magneto-structural transition in (Mn,Fe)1.95P0.50Si0.50 compounds

We report on structural, magnetic, and magnetocaloric properties of MnxFe1.95?xP0.50Si0.50 (x???1.10) compounds. With increasing the Mn:Fe ratio, a first-order magneto-elastic transition gradually changes into a first-order magneto-structural transition via a second-order magnetic transition. The study also shows that thermal hysteresis can be...

Magnetic properties of Dy nanoparticles and Al2O3-coated Dy nanocapsules

Tunable thermal hysteresis in MnFe(P,Ge) compounds

Structural, magnetic, and magnetocaloric properties of the MnFe(P,Ge) compounds were systematically studied on both bulk alloys and melt-spun ribbons. The experimental results show that the critical behavior of the phase transition can be controlled by changing either the compositions or the annealing conditions. The thermal hysteresis is found...