AFM Study of Potassium–Ammonium Hydrogen Sulfates at Lower Temperatures

Resumo

Surfaces of the natural cleavage of water-soluble single crystals (K_0.43(NH₄)_0.57)₃H(SO₄)₂ is studied via atomic force microscopy. It is shown that ultrafine details of nanorelief (pits and hills with stable parameters of height (depth) of ~0.7 nm form on the surfaces of crystals) correspond to 1/3 с in a unit cell. A phase transition (from paraelectric to ferroelectric) is detected in the (K_0.43(NH₄)_0.57)₃H(SO₄)₂ crystal via microscopy of the piezoelectric response as the temperature falls from 296 to 282 K.