  With the experimental data at the national nuclear data center, NNDC, we
investigate systematically the emerging nuclear structure properties in the
first 2+ excited energies, E(2+) and their energy ratios to the first 4+
levels, R = E(4+)/E(2+) in the nuclei over 28 < Z < 50 for protons, and 40 < N
< 70 for neutrons. By introducing the pseudo-shell configurations built on the
combined subshells, we explain the following phenomena; a semi-double shell
closure, a shape phase transition, and a reinforced deformation. The reinforced
deformation arises suddenly at Z = 40 (or 38), N = 60 and approaches a maximum
value, R = 3.3, as being centered at Z = 40, N = 64. We define this reinforced
deformation 'a ferro-deformation', as in the previous study [arXiv:1604.01017].
The shape coexistence would be expected to be, as forming a ferro-deformation,
with a strong rotational mode, and a near spherical shape, with a vibrational
mode, in the transitional region at N = 58, 60, and 62 for the nuclei, with Z =
38 and 40; 96Sr, 98Sr, 100Sr, and 98Zr, 100Zr, and 102Zr. We suggest that the
ferro-deformation should be closely associated with a strong spin-orbital
interaction between neutrons in the g7/2 orbital and protons in the g9/2
orbital. Such an isospin dependent spin-orbital interaction, with the same
angular momentum, l = 4, reinforces nuclear surface toward a sudden and
dramatic deformation, giving rise to the ferro-deformation at the critical
point, Z = 40, N = 64. We discuss the similarities and differences of the
ferro-deformation between the two critical points; Z = 40, N = 64 and Z = 64, N
= 104.
