LSAT (oxide)
From Wikipedia, the free encyclopedia
| Names | |
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| Other names
lanthanum aluminate - strontium aluminium tantalate | |
| Identifiers | |
3D model (JSmol) |
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PubChem CID |
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| Properties | |
| (LaAlO3)0.3(Sr2TaAlO6)0.7 | |
| Density | 6.74 g/cm3 |
| Melting point | 1,840 °C (3,340 °F; 2,110 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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LSAT is the most common name for the inorganic compound lanthanum aluminate - strontium aluminium tantalate, which has the chemical formula (LaAlO3)0.3(Sr2TaAlO6)0.7 or its less common alternative: (La0.18Sr0.82)(Al0.59Ta0.41)O3. LSAT is a hard, optically transparent oxide of the elements lanthanum, aluminium, strontium and tantalum. LSAT has the perovskite crystal structure, and its most common use is as a single crystal substrate for the growth of epitaxial thin films.
LSAT was originally developed as a substrate for the growth of high Tc cuprate superconductors thin films, mostly of yttrium barium copper oxide (YBCO), for microwave device applications. The motivation for its development was to create a lattice-matched substrate with a similar thermal expansion coefficient and no structural phase transition over a wide temperature range, spanning from the high temperatures used for the growth of cuprates, to the cryogenic temperatures where they are superconducting.[1]
Properties
LSAT has a Mohs hardness of 6.5, placing it between quartz and the mineral feldspar. Its relative dielectric constant is ~22 and it has a thermal expansion coefficient of 8~10×10−6/K. The thermal conductivity of LSAT is 5.1 Wm−1K−1.[2][3] LSAT's (cubic) lattice parameter of 3.868 Å makes it compatible for the growth of a wide range of perovskite oxides with a relatively low strain.[citation needed]
LSAT's melting temperature of 1,840C is lower compared to similar alternative substrates, such as LaAlO3. This property enables the growth of LSAT single crystals using the Czochralski process (CZ), which has commercial advantages.[4]
