The heteroepitaxy of a single crystal diamond has been carried out in the KTaO₃ substrate using Ir as a buffer layer. KTaO₃ has a perovskite lattice structure and displays a face-centered cubic structure. Its lattice constant is 3.98 Å, which is only 3% mismatched with the lattice constant of Ir of 3.84 Å, and also, its thermal expansion coefficient is 4.031 × 10⁻⁶/K, which is nearly close to that of diamond 3.85 × 10⁻⁶/K (at 1223 K), making it to be regarded as an alternate substrate of the heteroepitaxy of a single crystal diamond. The magnetron sputtering technique was used to deposit Ir thin films with a high orientation in the (001) direction on a KTaO₃ (001) substrate. Thereafter, bias enhanced nucleation on Ir surface was grown by direct current chemical vapor deposition (CVD) methods. At last, a single crystal diamond with a size of 10 × 10 × 0.78 mm³ has been grown, whose (004) rocking curve FWHM is 183 arc sec, which testifies to the excellent crystalline quality of the heteroepitaxial diamond film.

中文翻译：

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单晶金刚石在 Ir 缓冲 KTaO3(001) 衬底上的异质外延

使用Ir作为缓冲层在KTaO ₃衬底中进行了单晶金刚石的异质外延。KTaO ₃具有钙钛矿晶格结构并显示出面心立方结构。它的晶格常数为 3.98 Å，与 Ir 的晶格常数 3.84 Å 仅相差 3%，并且其热膨胀系数为 4.031 × 10 ^-6 /K，接近于金刚石的 3.85 × 10 ^-6 /K（1223 K），使其被视为单晶金刚石异质外延的替代衬底。磁控溅射技术用于在 KTaO ₃(001) 基材。此后，通过直流化学气相沉积 (CVD) 方法在 Ir 表面上生长了偏置增强的成核。最后生长出尺寸为10 × 10 × 0.78 mm ^{3 的}单晶金刚石，其（004）摇摆曲线FWHM为183弧秒，证明了异质外延金刚石薄膜的优良结晶质量。