新型有机非线性光学材料L-苹果酸脲薄膜形成机理及性质研究

通过控制加热温度，采用物理气相沉积(PVD)技术制备了新型有机非线性光学材料L-苹果酸脲(ULMA)的晶体薄膜，该薄膜保持了晶体良好的非线性光学性质. FTIR和XRD测试表明薄膜与ULMA晶体具有相同的组成与晶体结构. 热分析显示ULMA具有确定的熔点，是一种具有良好热稳定性的有机晶体，其蒸发温度低于底物尿素和L-苹果酸的分解温度. 在真空条件下，ULMA的分解温度与蒸发温度之差将加大，从而说明PVD法制备ULMA晶体薄膜是一种切实可行的方法，只要将加热温度控制在蒸发温度与分解温度之间，就可以制得ULMA晶体薄膜.

Mechanism and characteristics of the new organic nonlinear optical material urea L-malic acid film

A new nonlinear optical material urea L-malic acid film (ULMA) was successfully prepared by physical vapour deposition (PVD) at appropriate heating temperature. XRD and FTIR measurements show that the film and the ULMA powder have the same composition and crystal structure. Furthermore, the film keeps the nonlinear properties of the ULMA crystal. Thermal analysis shows that ULMA has good thermal stability with constant melting point. Its evaporation temperature is below the decomposition temperature of its substrates urea and L-malic acid. The difference between evaporation and decomposition temperature is increased in vacuum. Therefore, it is verified that the PVD method is a practical approach to prepare ULMA film if the heating temperature is controlled between the evaporation and decomposition temperatures.