3.?Results and Discussion3.1. Structural Analysis of Powders3.1.1. X-ray Diffraction StudiesFigure 2 shows the XRD patterns of mixed xWO3(1-x)Y2O3 powders for 2�� = 20��~65��. The main peaks for all samples are the same as the x is changed (matched with 1-0486, 2-0308, 5-0363, 44-0357, and 44-0399 JCPDS file numbers). A higher level of doping (x �� 0.85) shows a significant change in chemical composition as Y6WO12 is produced. Furthermore, the distance between similar atomic planes (d-spacing) in WO3 and Y2O3 is changed with ��d variation less than 10% as x is decreased. Maximum d-spacing of each sample occurs at a mean peak of XRD pattern and also can be determined from the Bragg Equation (n�� = 2dsin�� for n = 2, Bragg angel = ��, and �� = 1.
542 ?). In the case of x = 1 and at �� = 23.
184��, d-spacing from the XRD result is 3.8293 ?, whilst calculated d-spacing from the Bragg Equation is 3.9168?.Figure 2.XRD analysis of mixed powder for x = 1, 0.95, 0.9, 0.85, and 0.8.The average of crystallite size was determined from XRD results based-on the Scherrer Anacetrapib Equation (Scherrer Constant, K = 0.94 for spherical crystals with cubic symmetry [28] and �� = 1.542 ? from XRD results):FWHM=K��L cos��(1.a)then:L=K��(FWHM) GSK-3 cos��(1.b)Since K and �� are constant, the crystallite size is only related to the position (2��) and the Full-Width Half-Maximum (FWHM) value of the peaks. Table 1 shows the maximum, minimum, and average crystallite sizes of the samples determined from Equation (1.
b). Note that the calculation was carried out for the first 12 peaks of the XRD results.
Variations into the crystallite sizes in respect to Y2O3 co
Polymers based on lactic acid deserve great attention because they decompose by hydrolysis in the human body into nontoxic metabolites. Among the many applications found for these polymers in medicine, it is worth mentioning: a fracture fixer [1,2], surgical cord for the inner lesions suture [2�C6], various implants [7,8] and material for target therapy or controlled release of medications [9�C20]. The traditional method of poly(lactide) (PLA) synthesis required rigorous conditions: a high vacuum, long polymerization times and the consumption of great quantities of energy, using metal or metal oxide as a catalyst to speed up the reaction and minimize the pyrolysis by reducing the temperature [21�C29].