Your sample for the second phase is called a "volunteer sampling".

It doesn't sound like you had any "eligibility" requirements, and just accepted anyone who was willing to complete both the first survey and the later diary. In that case, the would each be a "convenience" sample.

Jen - You have used "Judgment sampling technique", it is an extension of convenience sampling based on judgement. For example , you have used a stipulation that participants had to be of a certain age, thus using some judgment. David L Morgan is very correct in saying that you had accepted anyone who was willing to complete both the first survey and the later diary and in that case, it is a "convenience" sample. Convenience sampling is also called as accidental sampling and is based on using participants who are a captive audience or shows special interest in research. But in your case, it can be called as "Judgment sampling" because you have used some judgment while choosing a convenience sample.

although you have used a criteria to select your sample,but that criteria is related to your topic,from among them you hvae done a random sampling method of selection.

Jen Smith, analysis of the quantitative data will give you some categories/groups of the respondents (depending upon your lenses of analysis). Then you may select individuals from those categories/groups for qualitative interviews.