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The MgxZn1-xO(x=0.1,0.2,0.3, 0.4,0.5,0.6 and 0.7)thin films were prepared on glass substrate by the Sol-Gel method. The X-ray diffraction results show that when the value of x is between 0.1 and 0.3, the thin film has the structure of hexagonal wurtzite while the angle of diffraction peak becomes bigger with increasing x, and the MgO impurity phase segregates at x=0.4. The ultraviolet photoluminescence spectra of the films show ultraviolet emission peak at room temperature, which has an increasing blue shift with the increasing content of Mg. The band gap of ZnO broadens with Mg-doping concentration increasing from 0.1 to 0.3. For the sample with x=0.1 annealed at 500℃, the crystal quality of the films is improved with the increase of the rate of temperature rise from 4.5℃/min to 6.0℃/min. For the sample with x=0.2, the crystal quality of the films is improved with the increase in annealing temperature from 500℃ to 560℃. With the annealing temperature increasing above 590 ℃ the crystal quality of the films degenerates.

The Co2+ ions doped ZnO diluted magnetic semiconductor films, Zn1-xCoxO, were prepared on glass substrate using PVA method. The structure of Zn1-xCoxO thin films with different x value and its photoluminescence properties were investigated. The vibrating sample magnetometer (VSM) measures the ferromagnetic properties of Zn0.88Co0.12O thin films at room temperature. We analyzed the influence of doping content on its luminescence performance, and discovered that with the doping content increasing, the blue luminescence peak shows a red shift.

SrFe12-x12-xCrxxO1919 (x=0—10) hexaferri te nanoparticles have been fabricated using a sol-gel technique for perpendicular magnetic recording. Experimental results have shown that the values of specific saturation mag netization, σss, increase for x≤04 as the Cr doping content incre ases, and reach maximum at x=02, while the coercivity, Hcc, decreas es for x＜05 This feature is favorable to magnetic recording. It is also fou nd that the α-Fe22O33 non-magnetic phase appears after x=06 and remai ns to be a hexagonal magnetoplumbite phase for x=0—04 Magnetic measurem ents have revealed that Cr substitution can decrease the magnetization and incre ase the peak-widening for Hopkinson peak when doped with Cr3+3+.

Using XRD and TEM techniques,the modification mechanism of Fe 3O 4 SrFe 12 O 19 particles has been studied.We have also studied the growth mechanism of spinel phase coating overlayer,and demonstrated that there exists a strong exchange coupling between coating overleyer and core particles due to the complexation of Fe 2+ ions in suspension and Fe 3+ ions extracted from the core particles.After modification,crystal structure and magnetic properties of SiFe 12 O 19 particles were modified.