Mn-O system

Figure 7.5 Variation of equilibrium oxygen partial pressure (a) equilibrium between a metal, Ag, and its oxide, Ag20, generates a fixed partial pressure of oxygen irrespective of the amount of each compound present at a constant temperature (b) the partial pressure increases with temperature (c) a series of oxides will give a succession of constant partial pressures at a fixed temperature and (d) the Mn-O system. [Data from T. B. Reed, Free Energy of Formation of Binary Compounds An Atlas of Charts for High-Temperature Chemical Calculations, M.I.T. Press, Cambridge, MA, 1971.]...

Peluso et al. (2003) DRIFTS Mn-O systems Structure function correlation Synthesis conditions + + + Total oxidation of ethanol... 

Figure 6.8 (a) Stability domains of various phases in the Mn-O system and the corresponding deviations in stoichiometry. (h) Phase diagram of Fe-O system, xq is mole fraction of oxygen, and (c) stability domains of the various phases in Fe-O systera. ... 

Fig. L Isobaric (= T0 atm) subsolidus phase relations in the manganese-rich portion of the Ca-Mn-O system.

Thackeray MM, de Kock A, Rossouw MH, Liles D, Bittihn R, Hoge D (1992) Spinel electrodes from the Li-Mn-O system for rechargeable lithium battery applications. J Electrochem Soc 139 363-366... 

Nicholas Grundy A, Hallstedt B, Gauckler LJ (2004) Assessment of the La-Sr-Mn-O system. Calphad 28 191-201... 

A particularly interesting example of CO behavior is observed in Mn—O systems such as Pri-xCaxMnOs (0.3 < x < 0.5) [20] and (La,Bi)i xCaxMn03 (0.5 < x < 0.7) [225], as the orbital degree of freedom associated with the Mn " sites results in a rich interplay between orbital and charge ordering as a function of bandwidth. 

Synthetic routes derived from molecular and non-molecular precursors have expedited the development of technologically important 2- and 3- dimensional materials. Such approaches have often proved superior to conventional ceramic techniques in that high purity bulk samples or thin films can be prepared at lower temperatures much more rapidly. Predominant among the precursor methods are those based on decomposition reactions. These either involve gaseous species, such as those used in chemical vapor deposition (CVD), or solids. Examples include the pyrolysis of the gas-phase precursor [(CH3)2A1(NH2)]3 to produce aluminum nitride (i) and the thermal decomposition of solid state carbonate precursors of calcium and manganese (Cai j,Mn C03, 0 < x < 1) to produce several of the known ternary compounds in the Ca-Mn-O system (2). Single-displacement reactions are also common as precursor methods. These approaches usually involve gas-phase reactions and are also used in CVD techniques. Examples here include the formation oi... 

Spinel electrode from the Li-Mn-O system for rechargeable lithium battery applications. 139 363-366. 

Although several compositions of Li -Mn O are possible with spinel structures, the AB2O4 spinel is the most desired spinel phase in the Li-Mn-O system due to its neat and flat de-intercalation to form a fully delithiated phase of X-Mn02. Gummow et al. used ternary phase diagrams shown in Figure 7.23 to review the utilisation of various Li-Mn-O phases in LIBs [37]. Improved capacity retention is demonstrated when a small amount of Mn in the spinel structure is replaced with Li, Mg or Zn. The improved cyclability... 

Triangular phase diagram for Li-Mn-O system with expanded emphasis on LiJVlnOj subsystem. (Reprinted with permission from Solid State Ionics, 69, R.J. Gummow et al.. Improved capacity retention in rechargeable 4 V lithium/Hthium manganese oxide (spinel) cells, 59-67, Copyright 1994, Elsevier.)... 

Historically, the research done on the Ca-Mn-O system has been performed at high (>1000°) temperatures.The traditional ceramic synthesis approach to these complex oxides involves repeated high-temperature firing of the component oxides with frequent regrindings. These severe reaction conditions are necessary to obtain a single-phase product because of the diffusional limitations of solid-state reactions. Such high-temperature syn-... 

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