  A new detection method using magnetization generated at triggered radiative
emission of neutrino pairs (RENP), $ |e \rangle \rightarrow | g \rangle +
\gamma + \sum_{ij}\nu_i \bar{\nu}_j $ (atomic de-transition from state $|e
\rangle $ to state $|g \rangle$ emitting sum of neutrino pairs
$\sum_{ij}\nu_i\bar{\nu}_j$ accompanied by a photon $\gamma$), is investigated
in order to determine unknown neutrino properties; absolute neutrino masses of
$\nu_i$ and Majorana/Dirac distinction. Magnetization associated with RENP
events has parity violating component intrinsic to weak interaction enforced by
crystal field effect in solids, and greatly helps background rejection of
quantum electrodynamic (QED) origin even when these backgrounds are amplified.
In proposed experiments we prepare a coherently excited body of trivalent
lanthanoid ions, Er$^{3+}$ (a best candidate ion so far found), doped in a
transparent dielectric crystal. The magnetic moment $\mu \langle
\vec{S}\cdot\vec{k} \rangle/k $ arising from generated electron spin $\vec{S}$
parallel to trigger photon direction $\vec{k}/k$ is parity odd, and is absent
in QED processes. The generated magnetic field of order nano gauss is stored in
crystals long after pair emission event till spin relaxation time. An improved
calculation method of coherent rate and angular distribution of magnetization
is developed in order to incorporate finite size effect of crystal target
beyond the infinite size limit in previous calculations.
