The Effects Of La Doping On The Crystal Structure And Magnetic Properties Of Ni2in-Type Mncoge1-Xlax (X=0, 0.01, 0.03) Alloys

In this experiment, a series of MnCoGe1-xLax (x = 0, 0.01, 0.03) alloy samples were prepared using a vacuum arc melting method. The crystal structure and magnetic properties of alloys were investigated using X-ray diffraction (XRD), Rietveld method, physical property measurement system (PPMS), and vibrating sample magnetometer (VSM) analyses. The results show that all samples were of high-temperature Ni2In-type phases, belonging to space group P6(3)/mmc (194) after 1373 K annealing. The results of Rietveld refinement revealed that the lattice constant and the volume of MnCoGe1-xLax increased along with the values of La constants. The magnetic measurement results show that the Curie temperatures (T-C) of the MnCoGe1-xLax series alloys were 294, 281, and 278 K, respectively. The maximum magnetic entropy changes at 1.5T were 1.64, 1.53, and 1.56 J center dot kg(-1)center dot K-1, respectively. The respective refrigeration capacities (RC) were 60.68, 59.28, and 57.72J center dot kg(-1), with a slight decrease along the series. The experimental results show that the doping of La results in decreased T-C, basically unchanged magnetic entropy, and slightly decreased RC.