16020

14308

كارشناسي ارشد

ماده چگال

اصفهان : دانشگاه صنعتي اصفهان

1399

چهارده، 85ص. : مصور، جدول، نمودار

پرويز كاملي

اسماعيل عبدالحسيني سارسري

حسين احمدوند، حميده شاكري‌‌پور

1399/08/28

كتابنامه

فيزيك

فيزيك

1399/08/28

2651404

Investigating the Effect of Cd Doping on Structural andMagnetic Properties of Ni Mn Sn Ferromagnetic Heusler Alloy Zahrasadat Ghazinezhad Department of Physics Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Parviz KameliKameli@ iut acAbstractIn this thesis the effect of Cd doping on structural magnetic and magnetocaloric properties of Ni Mn Snferromagnetic shape memory Heusler alloys has been studied Ni47Mn40Sn13 xCdx x 0 0 75 1 1 25 alloyswere prepared by mechanical alloying in this thesis For preparing the samples a stoichiometric mixture ofprimary materials were ball milled under an argon atmosphere for 30 hours Powder samples werecompacted and then encapsulated in quartz tubes under high vacuum and annealed for 16 hours at 950 Cfollowed by rapid quenching in ice water mixture The X ray diffraction pattern of the samples indicates thatthe samples with x 0 0 75 1 show single phase and have L21 structure but sample with x 1 25 go out ofsingle phase The martensitic transformation temperature enhanced for all doped samples to roomtemperature Change of the temperature is attributed to the valence electron per unit e a and latticeparameter Magnetic susceptibility of all samples indicates both magnetic and martensitic transitions Magnetocaloric effect was measured both directly and indirectly Magnetocaloric effect enhances by dopingCd instead of Sn Consequently magnetic entropy change increases from 7 6 J kg 1 K 1 for undoped sampleto the values of 11 2 13 1 and 12 0 for doped samples with x 0 75 1 and 1 25 respectively Directmagnetocaloric measurement shows that the adiabatic temperature change increases from 0 9 K for undopedsample to 1 5 K for the sample with x 0 75 Both direct and indirect measurements prove that doping of Cdenhances the value of magnetocaloric effect Keywords 1 Magnetocaloric effect 2 Ferromagnetic shape memory alloys 3 martensitictransformation 86

پرويز كاملي

اسماعيل عبدالحسيني سارسري

حسين احمدوند، حميده شاكري‌‌پور