No abstract

No abstract

Lanthanum hexaboride films have been deposited on a tungsten tip by pulsed laser deposition technique. The field emission studies have been performed in the conventional field emission geometry. The Fowler-Nordheim plot obtained from the current-voltage characteristic is found to be linear in accordance with the quantum mechanical tunneling phenomenon. A current density of 1.2×104A∕cm2 is drawn from the deposited tip. The field enhancement factor is calculated to be 5537cm−1, indicating that the field emission is from nanoscale protrusions present on emitter surface. The emission current-time plots show the very good stability of the emitter.

In this paper the equation of equilibrium for a nonhomogeneous isotropic elastic solid under shear has been solved in rectangular Cartesian coordinates as well as in cylindrical polar coordinates. The modulus of rigidity of the material is assumed to vary in lateral as well as vertical directions. As an example, the above solution has been used to solve the problem of a Griffith crack in an infinite solid under shear.

No abstract

No abstract

No abstract

No abstract