Fe₄O₂₀Pr₄Ti₄
rare earth oxide · rare earth ceramicFe4O20Pr4Ti4 is a rare earth oxide suitable as rare earth ceramic. Color: amber-brown. Fired at 1200°C from 3 precursors (Pr6O11, Fe2O3, TiO2). Workshop batch: 100g at €21.53. Compressive strength ~100 MPa; estimated 0.90 kg CO₂/kg (+309% vs clay brick). Notable: uv luminescent, visible absorber. Confidence: medium.
- forms at
- 1200 °C · high-fire
- replaces
- clay brick
- CO₂
- 309% higher than clay brick (0.90 vs 0.22 kg CO₂/kg; 4.1× higher)
- energy
- 100% higher than clay brick (6.00 vs 3.00 MJ/kg; 2.0× higher)
- compressive
- 100 MPa
- density
- 5.37 g/cm³
- crystal
- orthorhombic
- band gap
- 2.28 eV
- cost
- €215.30/kg · €21.53 / 100 g batch
- confidence
- medium (synthesis route)
- potential
- 0.37 · env 0.00 · novel 1.00 · struct 0.20 · lineage 0.50 · supply 0.10
- flags
- uv luminescent: Converts invisible ultraviolet into visible light. Signage panels, low-energy wayfinding tiles, emergency markings that draw their illumination from daylight rather than mains power. visible absorber: A real-colour solar-gain control layer. Where the body takes visible light into itself rather than reflecting it, the material becomes a selective heat collector — useful on thermal-mass walls, absorber panels, and warm-toned cladding.
Architectural potential
An iron-praseodymium-titanate rare-earth ceramic whose architectural specification rests on the paired luminescent and absorber chemistries rather than mass. At 100 MPa compression and 309 per cent higher embodied CO₂ than fired clay brick, volume use is unjustifiable; the slab earns its place through the warm amber-brown face that both absorbs solar gain and converts ultraviolet into a visible emission. Natural placements are signature surfaces in cultural and public buildings: wayfinding tiles in museum corridors that glow through the evening, south-facing sill inserts where the absorber behaviour doubles as a passive heat-collector, accent tiles in ceremonial thresholds, emergency markings in low-light circulation. The warm colour palette reads more at home in timber-heavy and rammed-earth contexts than the cooler praseodymium-cobalt sibling does, which opens rural and agricultural architecture as a natural field — barn conversions, visitor centres in nature reserves, heritage retrofits where the UV-luminescent behaviour enables mains-free wayfinding after dusk. Against fired clay brick the argument is singular capability rather than bulk surface. The caveat is supply and scale: €21.53 per 100 g batch, 300 g workshop ceiling, four rare-earth precursors including praseodymium oxide, and supply-chain score around 0.14. Specification is the single-tile feature, not the cladding run.
Material character
The slab reads a warm amber-brown with a faint orange flush from the iron-titanate matrix, warmer than the cooler cobalt-praseodymium siblings and closer to the tone of a weathered terracotta than to a fired glaze tile. At 5.37 g/cm³ in a 70×70×38 mm piece, the slab lifts two-handed, the depth pulling more weight than the footprint would suggest. Skin matte from the sinter with a subtle warm sheen; edges cold-cut, the diamond-kerf powder catching reddish along the cut. Under 365 nm excitation the body emits a soft peach-amber glow, close in hue to its base tone — a legible shift rather than a dramatic contrast, visible in low ambient conditions.
Recipe
100 g batch · peak 1200 °C| element | precursor | formula | mass | safety |
|---|---|---|---|---|
| Fe | iron(III) oxide (red) | Fe2O3 | 24.2 g | safe |
| Pr | praseodymium oxide | Pr6O11 | 51.59 g | moderate |
| Ti | titanium dioxide (rutile) | TiO2 | 24.21 g | safe |
- 1Ramp
- 2Hold
- 3Ramp
- 4Ramp
- 5Hold
- 6Ramp
- 7Ramp
UV-luminescent — emits visible light under 365 nm UV
Visible absorber — saturated color from bandgap in the visible range