Temperature can significantly affect X-ray diffraction (XRD) measurements because it influences the crystal lattice and atomic vibrations. Here’s how:
- Thermal expansion – As temperature increases, the crystal lattice expands, slightly increasing the distance between atomic planes. This can shift the positions of diffraction peaks to lower angles.
- Increased atomic vibrations – Higher temperatures cause atoms to vibrate more, which can decrease the intensity of diffraction peaks and slightly broaden them.
- Phase transitions – Some materials change their crystal structure at certain temperatures. XRD can detect these phase changes as new peaks appear or old peaks disappear.
- Stress or strain effects – Heating or cooling can induce thermal stress in the material, affecting peak shapes and positions.
- Low-temperature effects – Cooling can sharpen peaks because atomic vibrations are reduced, improving resolution for precise structure analysis.
In short, temperature affects the positions, intensities, and widths of XRD peaks, so careful temperature control is important when analyzing crystal structures or studying phase changes.