Low temperature structural studies of SrSnO3.

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Strontium stannate (SrSnO3) is a perovskite oxide with potential applications.
• Understanding its structural stability and phase transitions is crucial for materials design.
• Local structural disorder can influence macroscopic properties.

Purpose of the Study:

• To investigate the crystal structure and thermal expansion of polycrystalline SrSnO3.
• To identify any structural anomalies or phase transitions within the temperature range of 8-350 K.
• To explore the origin of observed anomalies, potentially related to local structural disorder.

Main Methods:

• High-resolution powder neutron diffraction.
• Variable temperature measurements from 8 K to 350 K.
• Analysis of individual lattice parameter thermal expansion.

Main Results:

• SrSnO3 crystallizes in the orthorhombic Pbnm space group.
• The orthorhombic structure is stable across the entire measured temperature range (8-350 K).
• An anomalous behavior in lattice parameter expansion was observed near 230 K.

Conclusions:

• The structural stability of SrSnO3 is confirmed in the studied temperature range.
• The anomaly at 230 K likely indicates the presence of polar nanodomains.
• This phenomenon is associated with local disorder in the octahedral tilt arrangements within the SrSnO3 lattice.