Spontaneous magnetization of the square 2D Ising lattice with nearest- and weak next-nearest-neighbour interactions

Abstract

We show that the square two-dimensional (2D) Ising lattice with nearest-(J) and weak next-nearest-neighbour interactions (J d ) can be mapped on a square 2D Ising lattice that has only nearest neighbour interactions (J*). For J d /J 55 1 the transformation equation has the simple formThis result can be used to derive expressions for several thermodynamic functions of the square 2D Ising lattice with weak next-nearest-neighbour interactions. As an example we consider the spontaneous magnetization and compare it with low-temperature series expansion results.

Monte Carlo Calculations of Magnetic Heat Capacity of La0.7Sr0.3-x MnO3-d

“…Onsager showed in 1944 that the 2D system presented a phase transition [21][22][23]. The aim of this work is to investigate the phase transitions for La 0.7 Sr 0.3−x MnO 3−δ .…”

Energetics of highly kinked steps edges

“…In the case that only nearest neighbour interactions are considered exact expressions for the step free energy and step edge stiffness can be derived [14]. However, the incorporation of next-nearest neighbour interactions leads to approximate expressions that are only accurate for weak next-nearest neighbour interactions [15,16].…”