2026-04-17T02:58:49Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/185432024-06-18T11:50:54Zcom_2072_452955com_2072_2054col_2072_453063

00925njm 22002777a 4500 dc Alleg, Safia author Chabi, Thaounza author Bensebaa, Nadia author Saurina Canals, Joan author Escoda i Acero, Ma. Lluïsa author Suñol Martínez, Joan Josep author 2020-10-09 Microstructure as well as magnetic, thermal and magnetocaloric properties of the mechanically alloyed Fe72Nb8B20 powders have been investigated by means of Mössbauer spectrometry, differential scanning calorimetry (DSC), and magnetic measurements. The Mössbauer spectrometry results showed the formation of nanostructured Fe(B) and Fe(Nb) solid solutions, Fe2B boride, and an amorphous phase. The endothermic and exothermic peaks that are observed in the DSC curves might be related to the Curie temperature, and the crystallization of the amorphous phase, respectively. The critical exponent values around the magnetic phase transition of the amorphous phase (TC = 480 K), are deduced from the modified Arrott plots, Kouvel-Fisher curves and critical isotherm examination. The calculated values (β = 0.457 ± 0.012, γ = 0.863 ± 0.136 and δ = 3.090 ± 0.004) are near to those of the mean field model, revealing a dominating role of magnetic order arising due to long-range ferromagnetic interactions, as the critical exponents are mean-field-like. The maximum entropy change and the refrigerant capacity values are 1.45 J/kg·K and 239 J/kg, respectively, under a magnetic field of 5 T This research was founded by the DGRSDT/MESRS-Algeria, the PHC-Maghreb 15 MAG07 program and the Spanish MINECO projects MAT2013-47231-C2-2-P and MAT2016-75967-P http://hdl.handle.net/10256/18543 Microestructura Microstructure Metalls de transició -- Aliatges Transition metals -- Alloys Metalls de transició -- Propietats magnètiques Transition metals -- Magnetic properties Metalls de transició -- Propietats tèrmiques Transition metals -- Thermal properties Anàlisi tèrmica Thermal analysis Espectroscòpia Mössbauer Mössbauer spectroscopy Investigation of the Critical Behavior, Magnetocaloric Effect and Hyperfine Structure in the Fe72Nb8B20 Powders