Reciting Sura Al-Fatiha is obligatory and compulsory in first and second Rak’ats. After Al-Fatiha, you must recite another Sura whether Sura Ikhlas or any other Sura. Reciting Sura Ikhlas or Sura Al-Qadr or Al-Kafiroon after Al-Fatiha in Salah has been mentioned in many Hadeeths.
‘Wassalam.