Identification of the neutralV4+impurity in cubic 3C-SiC by electron-spin resonance and optically detected magnetic resonance

Nominally undoped zinc-blende polytype 3C-SiC single crystals have been studied by conventional electron-spin resonance (ESR), by the magnetic circular dichroism (MCD) absorption technique, and by optically detected ESR via the MCD (MCD-ESR). Apart from the dominant ESR signal ascribed to residual boron acceptors, an anisotropic spectrum with many lines is observed near liquid-He temperatures. It collapses into a hyperfine octet for H∥[111]. This spectrum is identified as the anisotropic ${}_{}{}^2{}_{}{}^{}$E ground-state resonance of ${\mathrm{V}}^{4+}$(3${\mathit{d}}^1$) on the cubic Si site in 3C-SiC. Above 15 K this spectrum disappears and an isotropic hyperfine octet appears. It is interpreted as the motionally averaged spectrum of the anisotropic ${\mathrm{V}}^{4+}$ spectrum. The data are analyzed in terms of Ham’s theory of the dynamic Jahn-Teller effect for a ${}_{}{}^2{}_{}{}^{}$E state. A sharp optical line at 6681 ${\mathrm{cm}}^{\mathrm{-}1}$ has been found in MCD absorption. On this line the MCD-ESR of ${\mathrm{V}}^{4+}$ is observed, which identifies the line as being related to ${\mathrm{V}}^{4+}$. It is interpreted as the zero-phonon line of the ${\mathrm{V}}^{4+}$ ${}_{}{}^2{}_{}{}^{}$E${\to }^2$ ${\mathit{T}}_2$ crystal-field transition.