https://doi.org/10.1007/s100510050501
Singularity of the specific heat of two-dimensional random Ising models*
Faculty of Science and Engineering,
Tokyo Denki University, Hatoyama, Saitama, 350-03, Japan
Corresponding author: a inoue@u.dendai.ac.jp
Received:
26
February
1998
Revised:
15
May
1998
Accepted:
25
June
1998
Published online: 15 October 1998
The singularity of the specific heat is studied for the
dilution (J>J'>0) type and
Gaussian type random Ising models using the
Pfaffian method numerically. The type of singularity
at the paramagnetic-ferromagnetic phase boundary
is studied using the standard regression method using
data up to 
system size.
It is shown that the logarithmic type singularity is more reliable than the
double-logarithmic type and cusp type singularities.
The critical temperatures are estimated accurately for both the
dilution type and Gaussian type random Ising models.
A phase diagram relating strength of the randomness
and temperature is also presented.
PACS: 05.70.Jk – Critical point phenomena / 64.60.Fr – Equilibrium properties near critical points, critical exponents / 75.10.Nr – Spin-glass and other random models
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998
