. Hafnium dioxide (HfO2) is a material often used as a high-k dielectric for semiconductor gating applications. The Hf 4f photoelectron peak in the XPS spectrum of an ultrathin film of HfO2 obtained with an Al Ka source (a=0.83401 nm) and a spectrometer with a work function of 25.34 eV is measured at a binding energy of 17.56 eV. (h = 6.62607 x 10-34 J·s; c = 2.99792 x 108 m/s; 1 J = 6.2415 x 1018 eV) a) What is the energy, in units of J, of the Al Ka source? b) What is the kinetic energy, in units of eV, of the measured electron? What is the binding energy telling us? c) If the same sample was analyzed on an XPS of identical work function, but with a Mg Ka source (a=0.98900 nm), what binding energy would be the measured for the same photoelectron? What will be the kinetic energy?