When measuring PXRD for a thin film or powder sample I get strange peak shapes when using a Ge(220)x2 monochromator compared to using a soller slit. I am using a Rigaku Smartlab PXRD, measuring in Parallel Beam mode. The Ge(220)x2 is denoted for high resolution and often used here for thin film reflectivity or lattice mismatch detection. When I attempt to use this same method for other types of samples the spectra comes out completely strange. Is there a reason for this? Does the Ge(220)x2 method not work for standard powder or drop cast type samples?