Synthesis and characterization of single crystals Y3Fe 5O12 and Bi3Fe5O12 prepared via sol gel technique

Magnetic properties of nano-crystalline yttrium iron garnet, Y 3Fe5O12 and bismuth iron garnet, Bi 3Fe5O12 were studied. The samples were synthesized by using sol gel route. The gel were prepared using nitrates of yttrium and iron for the yttium iron garnet (YIG) and nitrates of bismuth and iron for the bismuth iron garnet (BIG). The raw materials were mixed and dissolved in citric acid and were stirred for 3 months in room temperature until the gel was observed. The X-ray diffraction pattern reveals the cubic structure of YIG and BIG samples at 700°C and 5007deg;C respectively. From the M-H diagrams it was found that the YIG and BIG samples have saturation magnetization, Ms of 27.2 Gs with rectangular hysteresis loop and 24.4 Gs with S hysteresis loop, respectively. It is evident from the FESEM micrographs that the rectangular loop shape (YIG) arises from the homogeneous and rounded micro structure as compared to the inhomogenous and random orientation micro structure (BIG) of the samples. From the Electron diffraction done on Transmission Electron Microscope, both of the samples were shown to be single crystals