Low-temperature heat capacity of layer structure lithium nickel oxide

Abstract Heat capacity of lithium nickel oxide of nearly stoichiometric composition (Li 0.99 Ni 1.01 O 2 ) was measured using an adiabatic calorimeter between 13 and 300 K. Abnormally large heat capacity was observed below 20 K, and it seems be related to the spin glass transition observed in the magnetic susceptibility measurements of nearly stoichiometric samples of Li 1− x Ni 1+ x O 2 . The heat capacity value above 100 K was compared with LiCoO 2 , and it was found that the heat capacity of Li 0.99 Ni 1.01 O 2 is much larger than that of LiCoO 2 in spite of almost the same atomic weight of Ni and Co. The heat capacity difference was discussed in terms of the lattice vibrations and bond strength in the crystals.