Design of Equipment for Thermal Studies

Abstract

A versatile metallurgical furnace for high temperature investigations of metals and alloys is described. Its uses to conduct thermal analysis and thermal treatments on beryllium-iron alloys are described in detail. In order to apply thermal analysis to these alloys, a special thermal crucible was designed and found successful.

Avoided criticality and slow relaxation in frustrated two-dimensional models

“…Here we consider a square lattice. The same model has been used to describe an array of Josephson junctions in a uniform transverse magnetic field; 12,13 in this case the A ij 's can be interpreted, up to a constant, as the line integral of the vector potential along the bonds and f is the number of flux quanta of magnetic field per unit cell. 13 The system is frustrated in that nonzero f , no matter how small, induces an irreducible density of topological defects, i.e., vortices all of the same sign.…”

“…(Recall that the maximum value is f = 1/2 which corresponds to the so-called "fully frustrated" XY model. 13…”

“…(Recall that the maximum value is f = 1/2 which corresponds to the so-called "fully frustrated" XY model. 13 ) Our Monte Carlo simulation uses single-site updates, in which each spin variable is updated according to the Metropolis method. (This corresponds to a "model A" 21 dynamics for a nonconserved order parameter.)…”