Low X-Ray Luminosity Galaxy Clusters. II. Optical properties and
  morphological content at 0.18 < z < 0.70
  This is the second of a series of papers on low X-ray luminosity galaxy
clusters, in which we present the $r^\prime$, $g^\prime$ and $i^\prime$
photometry obtained with GMOS-IMAGE at Gemini North and South telescopes for
seven systems in the redshift range of 0.18 to 0.70. Optical magnitudes,
colours and morphological parameters, namely, concentration index, ellipticity
and visual morphological classification, are also given.
  At lower redshifts, the presence of a well-defined red cluster sequence
extending by more than 4 magnitudes showed that these intermediate-mass
clusters had reached a relaxed stage. This was confirmed by the small fraction
of blue galaxy members observed in the central regions of $\sim$ 0.75 Mpc.
  In contrast, galaxy clusters at higher redshifts had a less important red
cluster sequence. We also found that the galaxy radial density profiles in
these clusters were well fitted by a single power law.
  At 0.18 $<$ z $<$ 0.70, we observed an increasing fraction of blue galaxies
and a decreasing fraction of lenticulars, with the early-type fraction
remaining almost constant. Overall, the results of these intermediate-mass
clusters are in agreement with those for high mass clusters.
