What does the Imam say between Al-Fatihah and the Surah in congregational prayer when he pauses; is there a specific supplication or does he just pause for a short while?

The Imam's silence in an audible prayer after reciting Al-Fatiha is legislated according to some scholars, to enable those led in prayer to recite it. During this silence, the Imam engages in remembrance (dhikr), supplication (du'a), or silent recitation. Imam Al-Nawawi said: "It is recommended for the Imam, according to this view, to remain silent after Al-Fatiha for the duration of the congregants' recitation of it." Some scholars are of the opinion that the Imam should recite the opening supplication (Du'a al-Istiftah) during this silence.