A High-quality single crystal of $\mathrm{CaF}{\mathrm{e}}_3{\mathrm{O}}_5$ was grown using the floating-zone method, enabling a precise investigation of its electronic phase transitions. Temperature-dependent resistivity measurements reveal two successive semiconductor-metal-insulator transitions at $\sim 299$ and $\sim 296\mathrm{K}$, which are identified via specific heat and thermal expansion data as the emergence of a charge-averaged (CA) phase and the formation of a $\mathrm{F}{\mathrm{e}}^{3+}\text{−}\mathrm{F}{\mathrm{e}}^{2+}\text{−}\mathrm{F}{\mathrm{e}}^{3+}$ trimeron in the charge-ordered (CO) phase in $\mathrm{CaF}{\mathrm{e}}_3{\mathrm{O}}_5$, respectively. Our results demonstrate that the occurrences of CO and CA phases in $\mathrm{CaF}{\mathrm{e}}_3{\mathrm{O}}_5$ exhibit a competitive relationship instead of forming simultaneously. Under applied pressure, the metal behavior vanishes above 0.13 GPa, with $\mathrm{CaF}{\mathrm{e}}_3{\mathrm{O}}_5$ exhibiting pure semiconductor/insulator behavior. This means that pressure stabilizes the CO phase in $\mathrm{CaF}{\mathrm{e}}_3{\mathrm{O}}_5$ by prompting the formation of a trimeron, offering an alternative route to control competing electronic orders in mixed-valent oxides.

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• Metal-insulator transition
• Single crystal materials
• Strongly correlated systems