The Effect of Substitution of Mn by Pd on the Structure and Thermomagnetic Properties of the Mn1-xPdxCoGe Alloys (Where x = 0.03, 0.05, 0.07 and 0.1)

Karolina Kutynia; Anna Przybył; Piotr Gębara

doi:10.3390/ma16155394

The Effect of Substitution of Mn by Pd on the Structure and Thermomagnetic Properties of the Mn_1-xPd_xCoGe Alloys (Where x = 0.03, 0.05, 0.07 and 0.1)

Materials (Basel). 2023 Jul 31;16(15):5394. doi: 10.3390/ma16155394.

Authors

Karolina Kutynia¹, Anna Przybył¹, Piotr Gębara¹

Affiliation

¹ Department of Physics, Częstochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland.

Abstract

In the present paper, the influence of partial substitution of Mn by Pd on structure, thermomagnetic properties, and phase transitions in the MnCoGe alloys was investigated. The studies of phase constitution revealed an occurrence of the orthorhombic TiNiSi-type and hexagonal Ni₂Ti- type phases. Deep analysis of the XRD pattern supported by the Rietveld analysis allowed us to notice the changes in lattice parameters and quantity of recognized phases depending on the Pd content. An increase of palladium in alloy composition at the expense of manganese induced a rise in the Curie temperature. The values of ΔS_M measured for the variation of external magnetic field ~5 T equaled 8.88, 23.99, 15.63, and 11.09 for Mn_0.97Pd_0.03CoGe, Mn_0.95Pd_0.05CoGe, Mn_0.93Pd_0.07CoGe, and Mn_0.9Pd_0.1CoGe alloy, respectively. The highest magnetic entropy change ΔS_M was observed for samples with Pd content x = 0.05 induced by magnetostructural transformation. The analysis of the n vs. T curves allowed confirmation of the XRD and DSC results of an occurrence of the first-order magnetostructural transition in Mn_0.95Pd_0.05CoGe and Mn_0.93Pd_0.07CoGe alloys samples.

Keywords: DSC measurements; X-ray diffraction; magnetocaloric effect; microstructure.

Grants and funding

This research received no external funding. The APC was funded by private vouchers of P.G.