Quantum size effect on the heat capacity of nickel nanolattice

Nearly exponentially decaying heat capacity was observed exceptionally in a well-characterized naturally assembled hexagonal closed packed lattice of 4.0 nm nickel nanoparticles (NPs). It was also associated with quantum jumps. These were however not observed in other NP sizes and have negligible effects of high magnetic fields. Magnetic susceptibilities in contrast revealed the evolution of quantum size effects with a decrease in particle size. They exhibited sharp rise below about 30 K and vestiges of saturations below 5 K. The sharp rise was explained by Curie-like characteristics of odd electrons, while the saturations tend towards the orthogonal even-like case.