Nanoobjects microscopy

Classification of the crystallization modes of amorphous films
Bagmut A.G., Bagmut I.A.
Department of Physics of the National Technical University “Kharkiv Polytechnic Institute” of Ukraine. NTU “KhPI” 2, Kyrpychova str., 61002, Kharkiv, Ukraine.
E-mail: agbagmut@gmail.com

Based on “in situ” electron microscopic studies with the method of video recording of phase transformations, following polymorphous crystallization modes in amorphous films have been identified according to their structural and morphological characteristics (Table).
Layer polymorphous crystallization (LPC) mode describes the nucleation and growth of a single-crystal layer in the field of the electron-beam impact on amorphous film (Fig. 1). In this case δ0= D0/a0, where a0 is a cell parameter of the growing crystal. D0 is an average crystal size at a time t = t0 (t0 is characteristic unit of time), after which the volume of the amorphous phase decreases by the factor of e = 2.718. For LPC mode δ0 is about several thousand (2000-5000) [1].
Island polymorphous crystallization (IPC) mode describes the nucleation and growth of a polycrystalline layer. In this case δ0= D0/Ω⅓, where Ω is the volume of the crystal unit cell. For IPC mode δ0 is about several hundred (100-1100).
Intermediate mode between LPC and IPC. For this case δ0 ~ 1100-2000.
Dendrite polymorphous crystallization (DPC) mode describes the nucleation and growth of dendrite in amorphous layer. In this case also δ0= D0/Ω⅓, where Ω is the volume of the crystal unit cell. For DPC mode δ0 ~ 3868.

Mode	Film	Deposition method	δ0	
LPC	Sb2S3	Thermal evaporation	4992	
	Cr2O3	Laser evaporation	3107	
	V2O3	Laser evaporation	4553	
	Ta2O5	Laser evaporation	3659	
IPC	ZrO2	Ion-plasma evaporation	118	
	ZrO2	Laser evaporation	904	
	Yb2O2S	Electron evaporation	1030	
Intermediate	Ta2O5	Laser evaporation	1783	
DPC	HfO2	Laser evaporation	3868	

1. Bagmut A. Relative length as a classification parameter of the crystallization mode of amorphous films // PAST.- 2022.- 1, P. 64-68.