An Indicator to Identify the Li[Ni1/2Mn3/2]O-4 (P4(3)32): DC-Susceptibility Measurements

To gain an insight into the inter-relationship between the electrochemical properties and the magnetism of Li[Ni1/2Mn3/2]O-4, the magnetic nature of two different Li[Ni1/2Mn3/2]O-4 samples was investigated by dc-susceptibility measurements. One was prepared by a single-step solid-state reaction technique [Li[Ni1/2Mn3/2]O-4 in a cubic phase (LNMO-C)], while the other was prepared by a two-step solid-state reaction technique [Li[Ni1/2Mn3/2]O-4 (P4(3)32) (LNMO-P)]. According to the structural and electrochemical analyses, LNMO-C was assigned as nonstoichiometric Li[Ni1/2Mn3/2]O-4, whereas LNMO-P was assigned as stoichiometric Li[Ni1/2Mn3/2]O-4 (P4(3)32). Both samples exhibited a ferromagnetic (FM) behavior below similar to 130 K. However, the FM parameters for LNMO-P, such as saturation magnetization (M-s) and transition temperature (T-c), were apparently different from those for LNMO-C. This suggests that magnetic measurements are a powerful tool to distinguish the stoichiometric Li[Ni1/2Mn3/2]O-4 (P4(3)32) from the nonstoichiometric phase. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3374338] All rights reserved.