In order to introduce structural defects into the π band with minimal distortions in the band, bulk samples of varying magnesium content were prepared. Point contact Andreev reflection measurements reveal that the density of states of the π band and the behavior of the energy gaps in field imply a relative increase of π band to band scattering with increasing magnesium deficiency. The results are consistent with the observed increase of the low temperature Hc2 value in magnesium deficient Mg B2. © 2007 American Institute of Physics.
Yates, K. A., Miyoshi, Y., Grunwell, J., Riggall, K., Cohen, L. F., Chen, S. K., … Serquis, A. (2007). The effect of magnesium vacancies on the π intraband scattering in Mgx B2 as determined by point contact Andreev reflection. Applied Physics Letters, 91(12). https://doi.org/10.1063/1.2786019