اﺛﺮ ﺟﺎﻧﺸﺎﻧﯽ ﻣﻀﺎﻋﻒ ﯾﻮن ﻫﺎي 3+Nd و 3+Dy ﺑﺮ ﺧﻮاص ﺳﺎﺧﺘﺎري، ﻣﯿﮑﺮوﺳﺎﺧﺘﺎري و ﻣﻐﻨﺎﻃﯿﺴﯽ ﻧﺎﻧﻮذرات ﻓﺮﯾﺖ ﺑﯿﺴﻤﻮت

Influence of Nd+3 and Dy+3 Ions CO-Doped on Structural and Microstructural and Magnetic Properties of Bismuth Ferrite Nanoparticles

در اﯾﻦ ﭘﺮوژه ﻧﺎﻧﻮذرات Bi0.6Dy0.4-xNdxFeO، ﺑﺎ ﻣﻘﺎدﯾﺮ (0/4 و 0/3 ،0/2 ،0/1 ،0/0 =x) ﺑﻪ روش ﺳﻞژل ﺗﻬﯿﻪ و ﺳﻨﺘﺰ ﺷﺪه اﻧﺪ. ﺧﻮاص ﺳﺎﺧﺘﺎري، ﻣﯿﮑﺮوﺳﺎﺧﺘﺎري و ﻣﻐﻨﺎﻃﯿﺴﯽ اﯾﻦ ﻧﺎﻧﻮذرات ﺑﺎ اﺳﺘﻔﺎده از آزﻣﻮنﻫﺎي ﭘﺮاش اﺷﻌﻪي اﯾﮑﺲ (XRD)، ﻣﯿﮑﺮوﺳﮑﻮپ اﻟﮑﺘﺮوﻧﯽ روﺑﺸﯽ (FE-SEM) و ﻣﻐﻨﺎﻃﺶﺳﻨﺞ ﻧﻤﻮﻧﻪ ارﺗﻌﺎﺷﯽ (VSM) در دﻣﺎي اﺗﺎق اﻧﺪازهﮔﯿﺮي ﺷﺪ. ﺑﺮازش اﻟﮕﻮي ﭘﺮاش ﭘﺮﺗﻮ X ﻧﻤﻮﻧﻪﻫﺎ، ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﯾﮏ اﻧﺘﻘﺎل ﻓﺎز از ﻟﻮزيرخ ﺑﺎ ﮔﺮوه ﻓﻀﺎﯾﯽ R3c ﺑﻪ راﺳﺘﮕﻮﺷﯽ ﺑﺎ ﮔﺮوه ﻓﻀﺎﯾﯽ pnma رخ داده اﺳﺖ. آﻻﯾﺶ دﯾﺴﭙﺮزﯾﻮم و ﻧﺌﻮدﻣﯿﻮم در ﺟﺎﯾﮕﺎه ﺑﯿﺴﻤﻮت ﻣﻮﺟﺐ ﮐﺎﻫﺶ ﭘﺎراﻣﺘﺮﻫﺎي ﺷﺒﮑﻪ، اﻧﺪازه ي ﺑﻠﻮركﻫﺎ و ﺣﺠﻢ ﺳﻠﻮل واﺣﺪ ﻣﯽﺷﻮد. ﺗﺼﺎوﯾﺮ FE-SEM ﻧﯿﺰ ﮐﺎﻫﺶ اﻧﺪازه ذرات را ﻧﺸﺎن ﻣﯽدﻫﺪ. ﺣﻠﻘﻪي ﭘﺴﻤﺎﻧﺪ ﻣﻐﻨﺎﻃﯿﺴﯽ ﻧﺎﻧﻮﭘﻮدرﻫﺎ ﻧﺸﺎن دﻫﻨﺪه ي ﺑﻬﺒﻮد ﺧﻮاص ﻣﻐﻨﺎﻃﯿﺴﯽ ﻧﺎﻧﻮذرات اﺳﺖ و ﯾﮏ رﻓﺘﺎر ﺷﺒﻪ ﻓﺮوﻣﻐﻨﺎﻃﯿﺴﯽ را ﻧﺸﺎن ﻣﯽدﻫﻨﺪ. ﺑﯿﺸﺘﺮﯾﻦ ﻣﻐﻨﺎﻃﺶ اﺷﺒﺎع ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮﻧﻪ 0/1=x ﺑﺎ ﻣﻘﺪار emu/gr 2/9509 و ﮐﻤﺘﺮﯾﻦ ﻣﻐﻨﺎﻃﺶ ﻫﻢ ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮﻧﻪ 0/4=x ﺑﺎ ﻣﻘﺪار emu/gr 0/2640 اﺳﺖ. ﻧﺘﺎﯾﺞ ﻣﻐﻨﺎﻃﯿﺴﯽ ﺑﺮ اﺳﺎس زواﯾﺎي ﭘﯿﻮﻧﺪي Fe-O-Fe و ﻣﻘﺪار ﻣﻤﺎن ﻣﻐﻨﺎﻃﯿﺴﯽ ﯾﻮﻧﻬﺎي ﺧﺎﮐﯽ ﻧﺎدر دﯾﺴﭙﺮزﯾﻮم و ﻧﺌﻮدﻣﯿﻮم ﻣﻮرد ﺑﺤﺚ ﻗﺮار ﮔﺮﻓﺖ

In this work Bi0.6Dy0.4-xNdxFeO3 (x = 0.0, 0.1, 0.2, 0.3 and 0.4) nanoparticles have been prepared and synthesized by sol-gel method. The structural, microstructural and magnetic peroperties of these nanoparticles were measured by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM) at room temperature. The analysis of X-ray diffraction patterns of nonoparticles show that a phase transition occurs from rhombohedral with R3c space group to orthorhombic with pnma space group. Substitution of Dy and Nd ions in Bi site reduces the lattice parameters, the unit cell volume and the nanocrystalline size of all compounds. FE-SEM images also show a decrease in particle size. The magnetic hystersis loop of the samples represent improvement in the magnetic properties of nanoparticles and a weak ferromagnetic behavior. The highest and lowest saturation magnetization occur in samples for x=0.1 and x=0.4 with the value of 2.9509 and 0.2640 emu/gr, respectively. The results of magnetic behaviour were discucced based on the bond angle of Fe-O-Fe and the magnetic moment of Dy and Nd rare earth ions.