Observation of two transition temperatures in the heat capacity of a two-dimensional ferromagnet

Absence of Ferromagnetism or Antiferromagnetism in One- or Two-Dimensional Isotropic Heisenberg Models

1966 • 7,497 citations

Possibility of a Phase Transition for the Two-Dimensional Heisenberg Model

1966 • 436 citations

Crystal Structure of (NH4)2CuCl4

1964 • 115 citations