O₁₄W₂Y₆
heavy oxide ceramic · thermal mass ceramicO14W2Y6 is a heavy oxide ceramic suitable as thermal mass ceramic. Color: neutral. Fired at 1250°C from 2 precursors (Y2O3, WO3). Workshop batch: 200g at €36.57. Compressive strength ~100 MPa; estimated 0.94 kg CO₂/kg (+326% vs clay brick). Notable: electrochromic tungstate. Confidence: medium.
- forms at
- 1250 °C · high-fire
- replaces
- clay brick
- CO₂
- 326% higher than clay brick (0.94 vs 0.22 kg CO₂/kg; 4.3× higher)
- energy
- 108% higher than clay brick (6.25 vs 3.00 MJ/kg; 2.1× higher)
- compressive
- 100 MPa
- density
- 6.25 g/cm³
- crystal
- orthorhombic
- band gap
- 2.43 eV
- cost
- €182.85/kg · €36.57 / 200 g batch
- confidence
- medium (synthesis route)
- potential
- 0.35 · env 0.00 · novel 1.00 · struct 0.20 · lineage 0.50 · supply 0.00
- flags
- 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 yttrium-tungstate heavy-oxide ceramic doubling as a thermal battery and an electrochromic switch: a small DC signal shifts transmission, so the same slab that stores daytime solar gain can also dim its visible face without mechanical shading. Natural placements are south-facing thermal walls in atria and double-skin façades where the body darkens as it heats and re-releases warmth after dark; trombe-wall infills in passive-house architecture that tune their own solar gain day to day; radiant-heat-storage panels in hypocaust floors with a visible switching layer at the room-facing surface. The dual capability is the whole argument. Compression sits at 100 megapascals, so the body is a surface layer and infill rather than a primary-structural wall element. The caveats are serious and compound. Embodied CO₂ runs three and a quarter times higher than fired clay brick, the supply-chain score sits at zero for pure yttrium-tungstate feedstocks, and the 36 euros per 200 g batch forbids bulk specification. This is strictly a signature insert — a single trombe-wall patch, one switching tile in a thermal-mass field, a small south-facing pane that signals the whole façade's behaviour — paid for by the unusual passive-plus-active combination rather than by the thermal storage alone.
Material character
At 6.25 g/cm³ in a 70×70×33 mm slab the weight lands firmly two-handed, a dense mid-range within the heavy-oxide family. The body reads neutral grey with a faint warm cast from the yttrium content, a colour specific to yttrium-tungstate perovskite-adjacents rather than the bluer stannate siblings. Surface sits vitrified matte from the 1250 °C fire; edges cold-cut with diamond-saw kerf bloom. Fully opaque at rest. Under applied voltage the switching behaviour drives the face toward a dusty blue-grey without geometric distortion. Against a pure yttrium-stabilised zirconia sibling the colour runs slightly cooler and the sinter reads marginally finer-grained, closer to a dense technical ceramic than to a traditional stoneware.
Recipe
200 g batch · peak 1250 °C| element | precursor | formula | mass | safety |
|---|---|---|---|---|
| W | tungsten trioxide (yellow) | WO3 | 40.63 g | moderate |
| Y | yttrium oxide | Y2O3 | 59.37 g | moderate |
- 1Ramp
- 2Hold
- 3Ramp
- 4Ramp
- 5Hold
- 6Ramp
- 7Ramp
Electrochromic — color switches under applied voltage (thin-film chemistry)