This document discusses acceptor and donor dopants in potassium sodium niobate (KNN) ceramic materials. It describes preparing batches of 50g of doped KNN formulations with varying concentrations of titanium, manganese, tin, and strontium dopants. X-ray diffraction (XRD) analysis showed that manganese and titanium dopants at 1% concentration caused a slight difference in the shape of peaks compared to undoped KNN, indicating a shrinkage of the lattice volume. The document also notes that tin did not enter into solid solution with KNN based on secondary tin oxide peaks appearing in the XRD trace and insolubility issues reported for tin in previous studies.

1. ACCEPTOR AND DONOR
DOPANTS IN KNN( POTASSIUM
SODIUM NIOBATE BASED
CERMICS
BY: HAMZA SUHARWARDI (MM-03)

2. INTRODUCTION
• It is peioelectric ceramic materials that is a promising alternative to lead-based
Piezo ceramics in the field of Electromechanical Conversion.
• American Elements manufactures potassium Sodium Niobate In both Research
and Bulk Quantity.

3. INTRODUCTION
• Nb2o5 was obtained from stanford materials corporation with 99.999% purity.
• whereas K2CO3 and Na2CO3 were obtained from fisher scientific with 99.9% anhydrous used.
• In addition to this, TiO2 was obtained from aldrich chemistry with 99.99%, and MnO2, SnO2, and SrCO3 were
obtained from aldrich with 99.9% purity each.
• Carbonates were dried at 300◦C, whereas all other oxides were heated at 900◦C for 24 h.
• 50 g of doped-KNN formulations
• Batches Of 50 g of Doped-KNN Formulations (K0.5Na0.5TixNb1−x O3−x/2 Where (0.0 ≤ X ≤ 0.05; K0.5Na0.5MnxNb1−x O3−x/2
Where (0.0 ≤ X ≤ 0.01) K0.5Na0.5NnxNb1−xO3−x/2 Where 0.0 ≤ X ≤ 0.03) And (K0.5Na0.5)1−xSrxNbo3 Where 0.0 ≤ X ≤ 0.07)
• It is prepared from dried raw powders in a hot condition (∼200◦C) to avoid the non-stoichiometric conditions caused by moisture,
especially in carbonates.

5. XRD (X-RAY DIFFRACTION)
• The XRD traces from KNN-50/50 doped with 1% Mn and 1% Ti both appear to be similar, but the
shape of 2θ ∼ 45◦ {220}, and {002} peaks shows a slight difference (figure 1). In both cases, the
intensity of the 2θ = 32◦ is lower than that of the undoped KNN. Increasing the concentration of Ti to
5% Ti emphasized the structural change observed at 1% Ti.
• There are a few studies on single Mn acceptor dopant in KNN. Peaks shifting toward higher 2θ is
evidence of shrinkage in the lattice volume, which took place for Mn2+ and Ti4+ acceptor dopants as
compared to the undoped KNN peak (shown in figure B : 2θ = 45–46◦ ).
• conversely, reported that XRD peaks shifted toward lower 2θ (i.e. Expansion in the lattice volume) in
the case of Mn4+ doped KNN. For KNN-50/50 doped with Sn4+, secondary peaks of SnO2 are visible
in figure 2. Moreover, within the resolution limits.

6. • There was no change in the trace of the major KNN peaks, confirming that Sn does not enter into
solid solution with KNN. investigated SnO2 and cuo co-doping in KNN and concluded that Sn4+
was not soluble after 1 mol%.
• It also reported insolubility issues for Sn4+ in KNN with secondary peaks visible in their XRD
data. The reasons behind the insolubility of Sn4+ issues in KNN is unclear, since Sn4+ has a
similar ionic radius to Nb5+ However, Sn4+ is more covalently bonded to O than Nb5+, which
may influence its solubility.

7. 7
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