  Three-dimensional (3D) magnetic textures attract great attention from
researchers due to their fascinating structures and dynamic behaviors. Magnetic
hopfion is a prominent example of 3D magnetic textures. Here, we numerically
study the mutual conversion between a Neel-type hopfion and a Neel-type toron
under an external magnetic field. We also investigate the excitation modes of
hopfions and torons in a film with strong perpendicular magnetic anisotropy. It
is found that the Neel-type hopfion could be a stable state in the absence of
the external magnetic field, and its diameter varies with the out-of-plane
magnetic field. The Neel-type hopfion may transform to a Neel-type toron at an
out-of-plane magnetic field of about 20 mT, where the cross section structure
is a Neel-type skyrmion. The hopfion and toron show different excitation modes
in the presence of an in-plane microwave magnetic field. Our results provide a
method to realize the conversion between a Neel-type hopfion and a Neel-type
toron, which also gives a way to distinguish Bloch-type and Neel-type hopfions.
