Li₁₂O₄₈Pr₁₂Te₅W₃
rare earth oxide · rare earth ceramicLi12O48Pr12Te5W3 is a rare earth oxide suitable as rare earth ceramic. Color: neutral. Fired at 1200°C from 3 precursors (Pr6O11, WO3, Li2CO3). Workshop batch: 100g at €30.39. Compressive strength ~100 MPa; estimated 0.90 kg CO₂/kg (+309% vs clay brick). Notable: uv luminescent, electrochromic tungstate. 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
- 6.00 g/cm³
- crystal
- trigonal
- band gap
- 3.21 eV
- cost
- €303.90/kg · €30.39 / 100 g batch
- confidence
- medium (synthesis route)
- potential
- 0.37 · env 0.00 · novel 1.00 · struct 0.20 · lineage 0.50 · supply 0.09
- 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. electrochromic tungstate: A voltage-switchable optical chemistry. In thin-film form a small DC signal shifts transmission from clear to tinted blue, opening the door to dimmable glazing and responsive partitions that do not need mechanical shading.
Architectural potential
A rare-earth ceramic carrying two functional overlays at once: ultraviolet-excited luminescence from the praseodymium, and voltage-switchable tinting from the tungstate chemistry. The body is not a volume element — compression sits at 100 MPa and the embodied CO₂ runs over three times that of a clay brick — so the material is bought for the capability, not the mass. At building scale this is a small-area overlay tile: a signage panel that glows under low-UV accent lighting and dims to a darker blue under a DC signal, a wayfinding tile in metro interiors and hospital corridors that draws its evening illumination from ultraviolet fixtures rather than mains LEDs, an accent cladding patch in theatre façades that darkens during a performance and clears at curtain. The coupling of the two flags is unusual: a surface that both emits and absorbs, that can be read passively and driven actively. Natural placements are cultural-building façades, interior signage registers in civic architecture, and atrium threshold tiles where the colour-shift becomes part of the daily rhythm. The caveat is multiple: €30.39 per 100 g batch, supply-chain score near zero on the praseodymium and tellurium content, and untested in architectural production at any scale beyond the individual tile. Specification belongs to prototype and signature-element work.
Material character
The fired body reads a neutral off-white with a faint warm cream undertone from the praseodymium, brighter than the tungsten-oxide siblings in the family and cleaner than the heavier Pr-W sibling. At 6.00 g/cm³ and 70×70×34 mm the slab handles with real rare-earth density, a heavier-than-expected two-finger lift for its footprint and a small step down from the 8.19 g/cm³ Pr-W sibling. Surface finishes matte from the 1200 °C sinter, the grain visible as a fine even dusting under raking light; edges cold-cut with diamond-saw kerf along the arris. Under a 365 nm UV source the face shifts to a saturated cool green — the praseodymium-emission signature — rather than the chartreuse of the gadolinium-bearing borosilicates.
Recipe
100 g batch · peak 1200 °C| element | precursor | formula | mass | safety |
|---|---|---|---|---|
| Li | lithium carbonate | Li2CO3 | 13.93 g | safe |
| Pr | praseodymium oxide | Pr6O11 | 64.21 g | moderate |
| W | tungsten trioxide (yellow) | WO3 | 21.86 g | moderate |
- 1Ramp
- 2Hold
- 3Ramp
- 4Ramp
- 5Hold
- 6Ramp
- 7Ramp
UV-luminescent — emits visible light under 365 nm UV
Electrochromic — color switches under applied voltage (thin-film chemistry)