W. Schnelle et al., Low temperature specific heat capacity of 3d transition metal chlorine boracites (T3B7O13Cl; T=Cr, Mn, Fe, Co, Ni, Cu, Zn or Mg), J THERM ANA, 56(1), 1999, pp. 365-370
The heat capacities of eight chlorine boracites T3B7O13Cl (T=Cr, Mn, Fe, Co
, Ni, Cu, Zn or Mg) have been measured in the temperature range 2 to 100 K.
Magnetic phase transitions occur below 20 K in the compounds studied excep
t in the two non-magnetic substances Zn3B7O13Cl and Mg3B7O13Cl. The magneti
c specific heat capacities give information on magnetic ground state of the
transition metals and the entropy related to the phase transitions.