Two conditions must be met in order for a Solar Ice Halo to appear: there must be hexagonal ice crystals in the upper atmosphere and the crystals must be less than 20.5um (micrometers) wide. And there must be a Sun. OK, three conditions.
Always block the Sun's disc when capturing images like this. That has two benefits: it protects your eyes and it eliminates lens flare. And it improves contrast and saturation. OK, three benefits.
Here I'm using the cap from a bottle of Johnny Walker Black Label blended Scotch whisky I happened to have handy.