Resumen:
The porosity of undoped and Zr- and Ti-doped graphites has been determined using ultra small and small angle neutron scattering, nitrogen adsorption and helium pycnometry To differentiate between open and closed in the neutron measurements the contrast matching technique was employed It is shown that the combination of the three techniques is necessary for an accurate determination of the porosity and for the assessment of the structural modifications arising from the doping which results in the transformation of open porosity to closed