New series of moduli components of rank 2 semistable sheaves on ${\mathbb{P}}^3$ with singularities of mixed dimension

We construct a new infinite series of irreducible components of the Gieseker-Maruyama moduli scheme $\mathcal{M}(k),k\ge 3$ of coherent semistable rank 2 sheaves with Chern classes $c_1=0,c_2=k,c_3=0$ on ${\mathbb{P}}^3$ whose general points are sheaves with singularities of mixed dimension. These sheaves are constructed by elementary transformations of stable and properly $\mu$-semistable reflexive sheaves along disjoint union of collections of points and smooth irreducible curves which are rational or complete intersection curves. As a special member of this series we obtain a new component of $\mathcal{M}(3)$.