Journal of Alloys and Compounds, cilt.791, ss.208-214, 2019 (SCI-Expanded)
© 2019 Elsevier B.V.The effects of annealing process and chemical pressure on the structural and magnetocaloric properties of CoMn1−xVxGe (x = 0.05 and 0.10) alloys have been studied. Rietveld refinement of XRD patterns revealed that all samples are single phase and they crystallize in hexagonal structure with a space group (P63/mmc) at room temperature. The structural phase transition temperature Tstruct decreases with increasing vanadium (V) content drastically in compare to CoMnGe alloy which exhibit a first order structural transition at around 450 K. The decrease in Tstruct. by substituting fourth element in CoMnGe-based alloys are discussed in frame of changing its valence electron concentration (e/a) values. We found that, alloys exhibiting a first order magneto-structural transition (FOMT) around room temperature, have an e/a value of 6.62–6.67. The e/a dependence of the magnetostructural transition temperature can be used as a guide to obtain an alloy with FOMT around room temperature.