Functionalization of Ca2MnO4–δ by controlled calcium extraction: Activation for electrochemical Li intercalation

Raman Spectroscopic Investigation and Electronic State Calculation for Ca2(Mn,Ti)O4 Black Pigments with High Near-Infrared (NIR) Reflectivity

“…Several researchers have investigated the NIR-reflective, electrical, magnetic, and thermal expansion properties of Ca 2 MnO 4 . For example, the electrical properties of Ca 2 MnO 4 -based materials such as (Ca,RE) 2 MnO 4 (RE = Pr, Nd, Sm), Ca 2 (Mn,Nb)­O 4 , and Ca 2 MnO 4−δ have been reported. − In addition, Ca 2 MnO 4 shows uniaxial negative thermal expansion by doping with Sr and Ti . The magnetic properties of (Ca,Sr) 2 MnO 4 have been investigated, and the corresponding solid solutions show antiferromagnetic interactions .…”

“…In this study, we employed Raman spectroscopy and density functional theory (DFT) calculations to analyze the crystal structure and electronic states. Several researchers have previously investigated the crystal structures of Ca 2 MnO 4 -based materials using X-ray, neutron, and electron diffraction studies. − ,− However, only a few researchers have conducted Raman spectroscopy of Ca 2 MnO 4 ; however, detailed assignments of the vibrational modes have not been achieved . Information about the electronic states, such as conduction and valence bands, of materials is important for determining their optical properties.…”

“…13−16,19−23 However, only a few researchers have conducted Raman spectroscopy of Ca 2 MnO 4 ; however, detailed assignments of the vibrational modes have not been achieved. 17 Information about the electronic states, such as conduction and valence bands, of materials is important for determining their optical properties. DFT calculations constitute an effective tool for characterizing the density of states (DOS) and vibrational modes.…”

Dysprosium doping of Ca2MnO4: Effect on crystal structure at room temperature and thermal behavior

“…Compounds in the CaO-Mn IV O2 system have received wide attention of researchers since several decades as they are promising candidates for various applications. They can be used as near-IR reflective black pigments [1], magnetic [2,3], dielectric [4,5,6,7], electrochemical [8] and thermoelectric materials [9,10,11]. Even though CaMnO3 is the most investigated end-member, the compounds with the general formula CaO(CaMnO3)n (n = 1,2,…,∞), i.e.…”