Antimony Tin Oxide (ATO) or Antimony-doped Tin Oxide

1. Product Identification

• Product name: Antimony Tin Oxide (ATO), Antimony-doped Tin Oxide

• Chemical name: Antimony tin oxide

• CAS number: 128221-48-7

• Chemical formula: SnO₂:Sb₂O₃ or Sb₂SnO₅ (doped compound)

• Physical form: Blue powder, approximately spherical nanoparticles

2. Key Technical Properties

Grade SnO₂(%) Sb₂O₃(%)

ATO-T85 85 15

ATO-T90 90 10

ATO-T92 92 8

ATO-T95 95 5

Property Value Notes

D50 (Particle Size) 3.0 µm

True Density 6.95 g/cm³ at 20 °C

BET Surface Area 47–85 m²/g Non-porous

Solubility /

Dispersibility

Water: Insoluble

Acetone: Dispersible

Ethanol: Dispersible

*Requires surfactants

(typ. 9.5:0.5

Ethanol:Water)

Thermal Stability Up to ~800 °C Stable without phase

transition of SnO2 host

3. Functional Role and Mechanism

• Intended technical functions:

◦ Electrical conductor / conduction pathway for antistatic coatings

◦ Optically transparent conductive component (formulations targeting >80%

visible transmittance)

◦ Antistatic additive for polymers and coatings

◦ Infrared/thermal absorber via free-carrier absorption

◦ Investigated in research literature as a charge transport or interfacial

material in perovskite solar cells.

◦ Catalytic support (nanoparticle surface as catalyst carrier)

• Mechanistic description:

◦ Sb⁵⁺ substitutes for Sn⁴⁺ at lattice sites, creating shallow donor states below

the conduction band minimum; the extra electron from Sb⁵⁺ populates the

conduction band and establishes n‑type conductivity.

◦ Crystal structure: Sb-doped SnO₂ with tetragonal rutile structure (space

group P4₂/mnm).

◦ The wide band gap (on the order of 3.2–3.8 eV) allows high visible-light

transmission while maintaining an electrically conductive network.

4. Applications

Established applications: 

Flame Retardants; 

Antistatic coatings (primary market application; 2-15 wt% loading in polyamide, acrylic resins); 

PET Catalyst & Plastics; Laser marking additives

Constraints: Extreme-temperature electronics requiring operation >800°C sustained (thermal decomposition limit of SnO₂ phase); High-moisture aqueous environments without protective coating (hygroscopic nanoparticle surface; charge trapping); Direct contact applications with strong oxidizing agents or highly reactive substances (incompatible per SDS); Applications requiring p-type conductivity (ATO is inherently n-type; Sb⁵⁺ doping cannot be reversed to p-type without fundamental reformulation); RF shielding applications >100 GHz (SnO₂ becomes lossy and opaque in microwave frequencies); Moisture-sensitive electronics below percolation threshold (<2 wt% loading; network disruption by surface hydration)

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