Structural characterization of slightly boron-deficient LiB, LiB0.9 and LiB0.8, under pressure

Area of Science:

• Materials Science
• Computational Chemistry
• Solid-State Physics

Background:

• Lithium borides are compounds with potential applications in various fields.
• Understanding their structural behavior under pressure is crucial for material design.
• Stoichiometric LiB has known structural properties, but boron-deficient variants require investigation.

Purpose of the Study:

• To investigate the structural properties of boron-deficient lithium borides (LiB(0.9) and LiB(0.8)) under varying pressures.
• To predict stable structures and phase transitions using computational methods.
• To compare the stability of boron-deficient phases with stoichiometric LiB.

Main Methods:

• Utilized particle swarm optimization for structure prediction.
• Performed computational investigations under applied pressure.
• Analyzed structural parameters and enthalpies to determine phase stability.

Main Results:

• Both LiB(0.9) and LiB(0.8) adopt chain structures at low pressures, similar to stoichiometric LiB.
• Phase transitions to layered structures occur with increasing pressure for both compositions.
• Enthalpy calculations indicate that boron-deficient structures are more thermodynamically favored than 1:1 LiB, even at ambient pressure.
• Higher boron deficiency appears to be favored as pressure increases.

Conclusions:

• Boron-deficient lithium borides exhibit distinct structural behaviors under pressure compared to stoichiometric LiB.
• The stability of boron-deficient phases suggests potential for novel material properties.
• Further research into these materials could lead to new technological applications.