Table 1 Values of the experimental ratio R _exp of the HAADF intensity I _HAADF of sublayer #1 to those of the three alloys (GaAs substrate, In_0.51Ga_0.49P and Al_0.26Ga_0.74As) contained in the sample and used as standards.

$\frac{I_{\text{HAADF}}(\text{Subl}\#1)}{I_{\text{HAADF}}(\text{GaAs})}$

$\frac{I_{\text{HAADF}}(\text{Subl}\#1)}{I_{\text{HAADF}}({\text{In}}_{0.51}{\text{Ga}}_{0.49}\text{P})}$

$\frac{I_{\text{HAADF}}(\text{Subl}\#1)}{I_{\text{HAADF}}({\text{Al}}_{0.26}{\text{Ga}}_{0.74}\text{As})}$