NiCl 2 (btd-d 4 ) a: A polycrystalline sample of NiCl 2 (btd) (8.63 mg) was immobilised in eicosane (9.22 mg) and sealed in a gelatin capsule. Magnetic susceptibility measurements were performed under field cooled (FC) and zero-field cooled (ZFC) conditions in a 0.01 T dc field from 2 K to 300 K.