Comparative study of ferroelectric (K,Na)NbO3 thin films pulsed laser deposition on platinum substrates with different orientation

We fabricated ferroelectric (K,Na)NbO
₃
(KNN) capacitors on Pt(111) or Pt(100) bottom electrodes with different substrate temperature by pulsed laser deposition. The annealing effect in O
₂
was also investigated. KNN film on Pt(100) substrate exhibited crystal grain clearly than that on Pt(111). The 2P
_r
and 2V
_c
, measured by ferroelectric tester, of Pt/KNN/Pt(111) for 400°C and 600°C were 4.28 and 4.58 μC/cm
²
and 1.21 and 0.469 V, respectively at applied voltage of 1 V. The 2P
_r
and 2V
_c
of Pt/KNN/Pt(100) capacitors for 710°C were 27.7 μC/cm
²
and 4.05 V at applied voltage of 5 V, respectively.