The paper presents the results of a computational thermo-kinetic model of laser heating of GeTe thin films and their subsequent thermoconductive and radiative cooling. A comparison of this model and experimental results of observing of reversible phase transitions in thin films under impact of nanosecond pulsed laser radiation with «top hat» beam intensity distribution was performed. It was shown that the subsurface crystallization of amorphous GeTe thin film obtained on SiO₂ substrates is started at threshold laser radiation energy density E = 7.5 mJ/cm². Then crystallization process propagates up to substrate primarily in the rhombohedral α-GeTe phase in the range of E = 18.6–32 mJ/cm² with the subsequent transition to the cubic β-GeTe phase in the range of E = 32–47.6 mJ/cm² reaching the necessary temperatures for corresponding transitions. The reverse crystalline-amorphous transition is started at the laser energy density 62 mJ/cm², when the film temperature reaches the melting temperature and is observed up to energy density 93 mJ/cm² without ablation damage. It was shown that the values of energy densities, required for α-/β-phase transitions and reamorphization for the films obtained on native oxidized p-Si (1 0 0) substrates in comparison with ones required for the same transitions in films on SiO₂ substrates are more on about 20–30%, because of significant higher thermal conductivity of p-Si (1 0 0) substrate. The high optical contrast in the spectral range from 200 nm to 22000 nm and high difference in electrical conductivity from σ_am = 0.66 Ω⁻¹ cm⁻¹ to σ_cr = 26.8 Ω⁻¹ cm⁻¹ between amorphous and cubic crystalline states was demonstrated. The observed experimental results are in good agreement with computational thermo-kinetic model.

本文介绍了GeTe薄膜的激光加热及其随后的导热和辐射冷却的计算热动力学模型的结果。进行了该模型与实验结果的比较，该实验结果是在具有“高顶礼帽”光束强度分布的纳秒脉冲激光辐射的作用下观察薄膜中可逆相变的。结果表明，在阈值激光辐射能量密度E  = 7.5 mJ / cm ^2时，在SiO ₂衬底上获得的非晶GeTe薄膜的表面下结晶开始。然后，结晶过程主要在菱面体α-GeTe相中传播，直至E  = 18.6–32 mJ / cm ^2的范围随后的转变为E  = 32–47.6 mJ / cm ²的立方β-GeTe相达到了相应转变所需的温度。当膜温度达到熔化温度时，以激光能量密度62 mJ / cm ²开始反向结晶-非晶转变，并且观察到直至能量密度93 mJ / cm ^2都没有烧蚀损坏。结果表明，与在自然氧化的p -Si（1 0 0）衬底上获得的薄膜进行相同的跃迁所需的能量密度值相比，在天然氧化的p- Si（1 0 0）衬底上获得的薄膜需要进行α-/β相变和重新定形。₂由于p -Si（1 0 0）衬底的热导率明显更高，因此衬底的含量更高，约为20-30％。在光谱范围从200nm至22000纳米，电导率高差从高光学对比度σ_是 = 0.66Ω ^-1 厘米^-1到σ _CR  = 26.8Ω ^-1 厘米^-1无定形和立方晶态之间被证明。观察到的实验结果与计算的热动力学模型非常吻合。