Site-Specific Pressure-Driven Spin-Crossover in Lu_1-ScFeO₃.

Area of Science:

• Materials Science
• Quantum Physics
• Solid State Chemistry

Background:

• Pressure-driven spin-crossover (PSCO) is a quantum phenomenon in transition-metal systems.
• Crystal-field theory suggests coordination environment influences PSCO, but experimental verification is lacking.

Purpose of the Study:

• To experimentally verify the influence of coordination environment on PSCO.
• To investigate site-specific PSCO in Lu$_{1-x}$Sc$_x$FeO$_3$ under pressure.

Main Methods:

• Synthesis of Lu$_{1-x}$Sc$_x$FeO$_3$ materials.
• X-ray emission spectroscopy to probe electronic states.
• Density Functional Theory (DFT) calculations to model PSCO behavior.

Main Results:

• Observed distinct PSCO responses for Fe$^{3+}$ ions in octahedral and trigonal-bipyramidal coordination.
• Fe$^{3+}$ in trigonal-bipyramidal sites exhibit PSCO above 100 GPa.
• Fe$^{3+}$ in octahedral sites show PSCO above 50 GPa.

Conclusions:

• The coordination environment critically dictates site-specific PSCO.
• Experimental evidence confirms the role of coordination in PSCO phenomena.
• Findings guide the rational design of PSCO materials for targeted applications.