[XeTeX] Changing font used by \cite{}

[Daniel Greenhoe]

Is there a way to change the font used by \cite{}, but without
changing the font of the entire document and without changing the font
used in the bibliography?

For example, suppose I do this:
  {\fontNew\cite{author2013}}

This changes the font of the author, but not the font of the title. Is
there a way around this?

I include many many citations in footnotes in a way similar to this:
  \footnote{\cite{...}}

I would like to define a font or macro that perhaps uses a sans serif
family of fonts with a scaled down size for use with \cite{} only:
  \footnote{\fontNew\cite{...}}

 I don't want this to affect the font I use for the other parts of the
text. I don't want it to affect the actual bibliography at the end of
the text.

Many thanks in advance,
Dan