Хрипко Сергій Леонідович2025-03-262025-03-262019https://jnep.sumdu.edu.ua/download/numbers/2019/4/articles/jnep_11_4_04037.pdf2077-6772https://ir.duan.edu.ua/handle/123456789/6016The paper is devoted to the searching for order parameter of low-temperature phase transitions in divalent nitrates Pb(NO3)2, Sr(NO3)2 and Ba(NO3)2. According to the curves of temperature dependencies of the quadratic susceptibility tensor component 14, the conclusion is made that the low-temperature phase transitions in divalent nitrates are the phase transitions of the first order with the features of the second order. The mechanisms of the low-temperature phase transitions in divalent nitrates are discussed from this perspective.en-USPhase transitionsDivalent nitratesOrder parameterQuadratic susceptibilitySignal intensity of second harmonic generation