Structure change of Mn₂O₃ under high pressure and pressure-induced transition

Abstract

Bixbyite (Mn,Fe)Pressure-induced phase transition was confirmed at about 21 GPa with a large hysteresis. The transition is reversible and non-quenchable. Powder indexing of the high-pressure phase was carried out using diffraction pattern taken at 35.06 GPa. It has a monoclinic symmetry and is not a corundum, Rh

High‐pressure phase transition in Mn2O3: Application for the crystal structure and preferred orientation of the CaIrO3 type

“…However, the 211 peak, diagnostic of the low‐ P phase, remains to 38.0 GPa, at which the phase transition completes (Figure 1d). This is consistent with Yamanaka et al [2005].…”

“…Syono et al [1985] reported a phase transition at 29 GPa. Yamanaka et al [2005] confirmed the transition and tentatively assigned a monoclinic unit cell to the high‐ P phase. However, the crystal structure of the high‐ P phase is not known.…”

“…At least 25 peaks are clearly resolved after annealing (Figure 2) and they are indexed well with an orthorhombic unit cell. Yamanaka et al [2005] tentatively assigned a monoclinic unit cell for the high‐ P phase. No angles deviate significantly from 90° in our monoclinic unit‐cell fitting.…”

“…No angles deviate significantly from 90° in our monoclinic unit‐cell fitting. In Yamanaka et al [2005]'s study, diffraction lines are significantly broader and only 11 diffraction lines were used for unit‐cell determination. The observed diffraction pattern of the high‐P phase agrees well with that of the CaIrO 3 type (Figure 2), which has been proposed for the crystal structure of the post‐perovskite phase in MgSiO 3 [ Murakami et al , 2004].…”

Ultra-oxidized rocks in subduction mélanges? Decoupling between oxygen fugacity and oxygen availability in a Mn-rich metasomatic environment

“…tetragonal to cubic structure(Irani et al, 1958); j: calculated from the cubic cell parameters given byMcMurdie et al (1950); k:Miletich et al (1998); l:Yamanaka et al (2005); m:Heines et al (1995); n: Curie temperature given byKrist et al (1992) (n* is the contribution of the magnetic effect to S 0 calculated as R ln(2s +1) (cf.Holland,1989), where s is the spin quantum number (1.5 for Mn 4+ )); o:Merkel et al (2002); p:Wang et al (2002); q:Dapiaggi et al (2003); r:Ohashi et al (2006); s: Kazanc et al (2006); t: Greeff et al. (2006); u: this study (see Appendix); v: Geller and Espinosa (1970); w:Robertson (1988).…”