Heat capacity study of Ti and Zn-doped magnetite

Heat capacities have been measured on single crystal specimens of magnetite containing low levels of Ti or Zn as a replacement for iron. A change in the nature of the Verwey transition from first to second or higher order was observed with increasing doping levels. This is in strict analogy with prior observations showing a similar change when the oxygen/iron ratio is increased beyond the 4/3 ratio. The entropy of the Verwey transition diminishes with increasing concentration of dopants.