The multiple electronic phase transitions as achieved in the metastable perovskite (
ReNiO
3,
Redenotes as the lanthanide rare-earth elements) by using a critical temperature, hydrogenation, electrical field and interfacial strain arouse considerable attentions in the field of condensed matter physics and material science that enable the promising applications in the field of critical temperature thermistor, artificial intelligence, energy conversion and weak electric field sensing. Nevertheless, the above abundant applications are still bottlenecked by the intrinsically thermodynamic metastability associated to
ReNiO
3. Herein, we synthesized the atomically flat
ReNiO
3film material with thermodynamic metastability by using laser molecular beam epitaxy (LMBE) that exhibits excellent thermally-driven electronic phase transitions. Noting the similar lattice constant between LaAlO
3substrate and
ReNiO
3film, this is attributed to the interfacial heterogeneous nucleation as induced by the template effect of as-used (001)-oriented LaAlO
3substrates. In addition, we clarify the critical role of
in situannealing upon an oxygen-enriched atmosphere in stabilizing the distorted perovskite structure associated to
ReNiO
3. Apart from the depositing process associated to LMBE, the
ReNiO
3with heavy rare-earth composition exhibits a more distorted NiO
6octahedron and a higher Gibbs free energy that is rather difficult to be synthesized by using physical vacuum deposition. As a representative case, the
in situannealing-assisted LMBE process cannot be utilized to deposit the SmNiO
3film, in which the impurity peaks associated to
Re
2O
3and NiO are observed in its XRD spectra. Assisted by the X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure, the valence state of nickel for
ReNiO
3was revealed to be +3, with the
t
2g
6
e
g
1configuration being observed. Considering the highly tunable electronic orbital configuration of
ReNiO
3associated to the NiO
6octahedron, co-occupying the A-site of perovskite structure with Nd and Sm elements regulates the transition temperature (TMIT) for
ReNiO
3within a broad temperature range. Furthermore, we demonstrate the anisotropy in the electronic phase transitions for Nd
1-xSm
xNiO
3, in which case the TMIT as achieved in the Nd
1-xSm
xNiO
3/LaAlO
3(111) heterostructure exceeds the one deposited on the (001)-oriented LaAlO
3substrate. The presently observed anisotropy in the electrical transportation for Nd
1-xSm
xNiO
3film materials is associated to the anisotropic in-plane NiO
6octahedron configuration as triggered by differently oriented LaAlO
3substrates. The present work is expected to introduce a new freedom to regulate the electronic phase transition and explore new electronic phase within
ReNiO
3material system, and pave ways toward growing atomically flat
ReNiO
3film material with expected electronic phase transition functionality.