An et al. Reply:

Figure 1

An x-ray EDXS spectrum obtained at 300 kV from individual $\tau -\mathrm{B}$ particles. Peaks are observed for B $K\alpha$ (180 eV) and Cu peaks (Cu $L\alpha \sim 950\mathrm{eV}$ Cu $K\alpha \sim 8.0\mathrm{keV}$, and $K_{\beta }\sim 8.7\mathrm{keV}$) from the TEM grid are visible, but peaks for the proposed impurity elements are not.