  The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, an unusual superconducting
state, defies high magnetic fields beyond the Pauli paramagnetic limit. It
exhibits a spatial modulation of the superconducting order parameter in real
space and is exceptionally rare. Recently, an even more exotic variant - the
orbital FFLO state - was predicted and identified in the transition metal
dichalcogenide superconductor 2H-NbSe2. This state emerges in thin samples with
thicknesses below ~40 nm, at the boundary between two and three dimensions. The
complex interplay between Ising spin orbit coupling and the Pauli paramagnetic
effect can lead to a stabilization of the FFLO state in a relatively large
range of the magnetic phase diagram, even well below the Pauli limit. In this
study, we present experimental evidence of the formation of this orbital FFLO
state in bulk 2H-NbSe2 samples. This evidence was obtained using
high-resolution DC magnetization and magnetic torque experiments in magnetic
fields applied strictly parallel to the NbSe2 basal plane. Both quantities
display a crossover to a discontinuous first-order superconducting transition
at the normal state boundary in magnetic fields of 4 T and above. This is
usually seen as a sign that Pauli paramagnetic pair breaking effects affect the
superconducting state. The magnetic torque reveals a small step-like reversible
anomaly, indicating a magnetic field-induced thermodynamic phase transition
within the superconducting state. This anomaly bears many similarities to the
FFLO transitions in other FFLO superconductors, suggesting the potential
existence of an orbital FFLO state in bulk 2H-NbSe2 samples. Additionally, we
observe a pronounced in-plane 6-fold symmetry of the upper critical field in
the field range above this phase transition, which has previously been
interpreted as a hallmark of the orbital FFLO state in thin 2H-NbSe2.
