Elastic Properties of Potassium Lithium Hydrogen Sulphate Crystal: An Ultrasonic Study

The anisotropy in the elastic properties of K₄LiH₃(SO₄)₄, single crystal is well studied by ultrasonic Pulse Echo Overlap [PEO] technique. The phase transition studies above room temperature were investigated by the temperature variation studies of elastic stiffness-constants in the range 300–420 K using PEO and found change of slope of the curves C₄₄ and C₆₆ at 340 K and weak elastic anomalies have been observed around 400 K.

Keywords:

• Lithium Potassium Hydrogen Sulphate
• Pulse Echo Overlap
• Elastic constants

Acknowledgment

One of the authors (GV) thanks UGC for a teacher fellowship.

Paper originally presented at AMF-4, Bangalore, India, December 12-15, 2003.

Notes

^#C₁₃ = 1/sc[m³−m²A+mB+C/D]^1/2 − C₄₄ and ^§C₁₆ = ½[(ρ ν₁ ² − ρ ν₂ ²) − (C₁₁ + C₆₆)²]^1/2. Where s = sin θ,c = cos θ and θ = 38° from c-axis.

_*C₁₂ = 1/sc{[((C₁₁s²+C₆₆c²+2C₁₆sc) − ρ ν²)((C₆₆s² + C₁₁c²) − ρ ν²)]^1/2 − (C₆₆sc+C₁₆s²)}. Where s = sin θ,c = cos θ and θ = 45° from the a-axis.