Composition dependence of lattice spacing for low dislocation density undoped liquid encapsulated Czochralski GaAs crystals

Crystals with varied composition were pulled by the As‐partial‐pressure controlled liquid encapsulated Czochralski method. The dislocation density was found to be as low as 2×103 cm−2 at the cores of the crystals. Lattice spacing (d) was measured with a precision of Δd/d ∼ 5.9 × 10−6 using synchrotron radiation. For a variation of 7×10−5 in the As‐atom fraction in the crystals, the lattice spacing varied by less than 1×10−5 A.