Aterm dont support ttf fonts. To bad.
Maybe you can compile or use another terminal to get a better font.
To list another fonts to use with aterm you can list them with xlsfonts.
And for use them you can use first the use the -fc command like this
aterm -fc "-sony-fixed-medium-r-normal--0-0-100-100-c-0-iso8859-1"
So the file .Xdefaults in the tc home directory that tries to use Luxi Sans font
dont work at all for the aterm.