  With the advances in miniaturization, understanding and controlling
properties of significant technological systems like silicon in nano regime
assumes considerable importance. It turns out that small silicon clusters in
the size range of 15-20 atoms are unstable upon heating and in fact fragment in
the temperature range of 1200 K to 1500 K. In the present work we demonstrate
that it is possible to stabilize such clusters by introducing appropriate
dopant (in this case Ti). Specifically, by using the first principle density
functional simulations we show that Ti doped Si$_{16}$, having the Frank-Kasper
geometry, remains stable till 2200 K and fragments only above 2600 K. The
observed melting transition is a two step process. The first step is initiated
by the surface melting around 600 K. The second step is the destruction of the
cage which occurs around 2250 K giving rise to a peak in the heat capacity
curve.
