Experimental X-ray Charge-Density Studies─A Suitable Probe for Superconductivity? A Case Study on MgB.

Case studies of 1T-TiSe and YBaCuO have demonstrated that X-ray diffraction (XRD) studies can be used to trace even subtle structural phase transitions which are inherently connected with the onset of superconductivity in these benchmark systems. However, the utility of XRD in the investigation of superconductors like MgB lacking an additional symmetry-breaking structural phase transition is not immediately evident. Nevertheless, high-resolution powder XRD experiments on MgB in combination with maximum entropy method analyses hinted at differences between the electron density distributions at room temperature and 15 K, that is, below the of approx.