Why is 「パッと」 part Katakana and part Hiragana?


I have run across this onomatopoeia twice now in music lyrics:

> [打上花火 by DAOKO × 米津玄師](https://www.youtube.com/watch?v=-tKVN2mAKRI)：
> 「パッと光って咲いた 花火を見てた」

> [GHOST by 星街すいせい](https://www.youtube.com/watch?v=IKKar5SS29E)： 「パッと弾けた感情に」

Having seen this occur twice now, I felt it was safe to assume that this is
not merely a stylistic choice made by the lyricists. This was reinforced when
I looked it up [on Jisho](https://jisho.org/word/%E3%81%B1%E3%81%A3%E3%81%A8),
which lists the main spelling as パッと instead of パット or ぱっと.

From what I can remember, I have never seen another word spelled like this,
with part of it being ひらがな and part of it being カタカナ. Or at the very least, if
I have, this one feels particularly curious, since I have always figured that
the small っ／ッ characters act as a fixed construct where they are modifiers of
the following syllable's consonant; like they're attached. So, if anything, I
would expect the word to be spelled ぱット or パっと, with the っ／ッ sharing the
script of the succeeding character.

What's going on here? _Why_ is it this way, or, _how_ did it come to be this
way?

Secondarily, are there any other words that share this characteristic?




This と is essentially the same as in と言う or と思う. In this case it makes an
adverb out of the small sound word before it. Similar examples include ギュッと
and ボーッと.




This と is essentially the same as in と言う or と思う. In this case it makes an
adverb out of the small sound word before it. Similar examples include ギュッと
and ボーッと.

