10180

9398

كارشناسي ارشد

فيزيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

1393

[نه]، 101ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

پرويز كاملي

حسين احمدوند

11/3/94

هادي سلامتي، اسماعيل عبدالحسيني سارسري

1396/10/02

كتابنامه

فيزيك

فيزيك

ID9398

103 The effect of zinc dopping and Polyvinylpyrolidone PVP coating on structural and magnetic properties of Co1 xZnxFe2O4 ferrite nanoparticles Elnaz Jaberolansar e jaberolansar@ph iut ac ir Date of submission 2015 17 01 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr Parviz Kameli kameli@cc iut ac ir Abstract Recently magnetic nanoparticles due to exclusive and useful characteristics have been used indifferent fields There are different synthesis techniques proportional to the researcher s purpose In thisstudy we choosed sol gel auto combustion method because of high homogeneity and purity of particles andability to work in rather low temperatures This study consist of three parts In the first part we haveinvestigated the effect of Zn on the structural and magnetic properties of cobalt ferrite nanoparticles in theform of Co1 xZnxFe2O4 x 0 0 1 0 3 0 5 0 7 In the second part the effect of sintering temperature at 350and 1000oC and then in the third part the effect of Polyvinylpyrolidone PVP coating on structural andmagnetic properties of Co0 3Zn0 7Fe2O4 ferrite nanoparticles annealed at 350oC have been studied usinganalysis such as XRD FTIR FE SEM TEM VSM and ac susceptibility The XRD patterns of the samplesannealed at 350oC indicated irregular behavior in lattice constant changes This irregular behavior isattributed to the cation distribution among spinel sites The lattice constant of the samples annealed at1000oC indicated a regular linear behavior that can be attributed to the redistribution of cations The VSMof 350oC sintered nanoparticles showed that by increasing Zn doping level the magnetization and coercivitydecrease Magnetization decreases due to the reduction of octahedral sites magnetization and the increaseof the magnetization of tetrahedral sits But in nanoparticles which was annealed at 1000oC by increasingZn doping level up to x 0 3 the magnetization increased and it decreased by further increase in x Theincrease of magnetization for x 0 3 is due to the increase of octahedral and the decrease of tetrahedralsites magnetization On the other hand the magnetization s reduction after x 0 3 due to the weakening ofthe superexchange interaction at the octahedral sites XRD patterns of PVP coated Co0 3Zn0 7Fe2O4nanoparticles indicated no change in structural phase of nanoparticles and after coating the crystallite sizedecreased Magnetic measurements indicated that with increasing the content of PVP magnetizationdecreased due to the reduction of the effective mass Key words Sol gel Co Zn ferrite cation s redistribution effect of temperature PVP

پرويز كاملي

حسين احمدوند

هادي سلامتي، اسماعيل عبدالحسيني سارسري