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 tuned by varying the Mn:Fe ratio. Small thermal hysteresis (less than 1 K) can be obtained while maintaining a giant magnetocaloric effect. This achievement paves the way for real refrigeration applications using magnetic refrigerants. 
N. H. Dung, L. Zhang, Z. Q. Ou, E. Br\"uck
cond-mat.mtrl-sci cond-mat.str-el