Compound characterization data — Sharma et al., 2026

SnTe@S, SnTe@P, and SnTe@V
XRD	All three samples showed sharp Bragg reflections indexed to cubic rock-salt Fm3̅m, JCPDS No. 08-0487, with no impurity peaks detected, confirming phase purity. For the (220) reflection: SnTe@S, broadest peak, FWHM = 1944 arcsec at 2θ = 28.22°, reflecting smaller crystallite size and higher disorder; SnTe@P, narrower peak, FWHM = 985.5 arcsec at 2θ = 28.26°, consistent with larger crystallite size; SnTe@V, sharpest reflection, FWHM = 695.1 arcsec at 2θ = 28.36°, evidencing enhanced crystallinity and lattice modification induced by V incorporation. The 0.10° (360 arcsec) shift toward a higher angle in SnTe@V indicated unit-cell contraction
XRD acquisition	High-resolution X-ray diffraction with Cu Kα radiation, λ = 1.5406 Å
XPS	Survey spectra confirmed Sn and Te as dominant constituents in all samples; the V 3p feature, expected at 32–46 eV, was weak in wide scans because of overlap and low dopant concentration, while high-resolution scans unambiguously confirmed V incorporation. Sn 3d: doublet at 485.6 eV (Sn²⁺ in SnTe) and higher-energy peak at 487.3 eV (Sn⁴⁺ from surface SnO₂). Te 3d: 571.5 eV (Te²⁻ in SnTe) and 575.6 eV (Te⁴⁺ from TeO₂), confirming partial surface oxidation. SnTe@S and SnTe@V both exhibited systematic positive core-level shifts relative to SnTe@P. The high-resolution V 3p spectrum was broad and asymmetric, with contributions from V²⁺, V³⁺, V⁴⁺, and V⁵⁺, confirming successful incorporation of V into the SnTe lattice; the orbital-component labels immediately before the four Sn/Te binding energies are not rendered in the PDF
XPS acquisition	High-resolution X-ray photoelectron spectroscopy with Al Kα radiation, hν = 1486.6 eV
TEM particle morphology and size	All samples showed quasi-spherical nanoparticles; Gaussian-fitted mean particle sizes were 26.4 ± 18 nm for SnTe@S, 49.2 ± 13 nm for SnTe@P, and 52.2 ± 12 nm for SnTe@V. SnTe@S showed aggregated grains and numerous grain boundaries, indicating a polycrystalline disordered structure; SnTe@P showed smoother surfaces; SnTe@V displayed the sharpest lattice fringes and most ordered facets; high-resolution TEM showed well-defined lattice fringes consistent with SnTe planes, JCPDS 08-0487
SAED	SnTe@S showed diffuse rings of weak intensity, consistent with partial amorphization and surface disorder; SnTe@P exhibited distinct diffraction spots; SnTe@V presented sharp, bright reflections, confirming enhanced crystallinity upon V doping in agreement with XRD
STEM-EDS	Homogeneous Sn and Te distribution in all samples and uniform incorporation of V in SnTe@V; V concentration in SnTe@V = 1.96 at. %; the glyph immediately before 1.96 is not rendered in the PDF
TEM and EDS acquisition	High-resolution transmission electron microscopy at 300 kV, equipped with energy-dispersive X-ray spectroscopy
Raman	Prominent A₁ optical-phonon and E₁ transverse-optical modes at approximately 115.3 and 137.2 cm⁻¹; in SnTe@V, both modes showed an approximately 0.8 cm⁻¹ blue shift relative to SnTe@P, and their FWHM was approximately 1.0 cm⁻¹ narrower than in SnTe@P, confirming enhanced crystallinity upon V doping; SnTe@S showed an approximately 1.3 cm⁻¹ red shift and asymmetric broadening of both modes. Asymmetry parameter A = 1.84 for SnTe@S and approximately 1.0 for SnTe@P and SnTe@V; the asymmetry reflects extensive surface amorphization in SnTe@S; the formula defining A contains unrendered symbols in the PDF
Raman acquisition	532 nm excitation laser
Photoluminescence	Room-temperature spectra for SnTe@P, SnTe@V, and SnTe@S showed broad defect-related emissions originating from Sn/Te vacancies, interstitials, and surface O impurities; SnTe@P showed the strongest intensity; SnTe@V showed reduced emission; SnTe@S showed quenched photoluminescence
Photoluminescence acquisition	300 lines/mm grating and Si CCD detector
FTIR	Characteristic Sn–Te–Sn and Te–Sn–Te modes in all samples, with additional Sn–Te–V features confirming V incorporation; peaks near 1230 and 1830 cm⁻¹ were assigned to C–O–H stretching and H–O–H bending from surface oxidation and carbon contamination; SnTe@S showed a suppressed Sn–Te scissoring dip at approximately 2913 cm⁻¹
Optical band gaps	Estimated from FTIR–Tauc plots because intrinsic-defect Urbach tails in the UV–Vis–NIR spectra obscure accurate band-gap determination due to interband states: SnTe@P, 390 meV; SnTe@S, 430 meV; SnTe@V, 370 meV; the expressions immediately preceding all three band-gap values are not rendered in the PDF
Low-temperature ESR acquisition	Main p. 5 describes low-temperature magnetoconductance measurements at 7 K using X-band (9.7 GHz) electron paramagnetic resonance spectroscopy; Main pp. 9–10 call the technique ESR and specify continuous-wave operation and zero-field conditions. The signal, proportional to the first derivative of the cavity quality factor Q with respect to magnetic field, dQ/dB, was obtained by modulating the magnetic field under lock-in detection conditions. The Q factor reflects sample conductivity and energy absorption, making signal intensity linearly dependent on conductivity variations. Magnetoconductivity was obtained by integrating differential magnetoconductivity data from the ESR spectra; integrated ESR absorption is proportional to the change in electrical conductivity, Δσ, and thus to conductance, ΔG; differential and integrated magnetoconductivity curves were fitted with the Hikami–Larkin–Nagaoka model
Hikami–Larkin–Nagaoka model	Equation 4 is printed as Δσ(B) = −αe²/(πh)[ln(B(φ)/B) − ψ(1/2 + B(φ)/B)], where α is the WAL prefactor, Ψ is the digamma function, e is the electronic charge, and h is Planck’s constant; the equation uses lowercase ψ while the following definition uses uppercase Ψ. The source prints B(φ) = h/(8πeHl(φ)) as the characteristic magnetic field, where H is the applied magnetic field and l(φ) is the phase-coherence length; this printed expression is retained as given
ESR-derived magnetoconductance and weak antilocalization	The WAL feature appeared as a cusp-like negative magnetoconductance signature originating from topological surface states. Hikami–Larkin–Nagaoka fits at 7 K gave (prefactor α, phase-coherence length l(φ)): SnTe@S, (0.55 ± 0.1, 5.5 ± 1.5 nm); SnTe@P, (0.73 ± 0.12, 7.2 ± 1.8 nm); SnTe@V, (1.8 ± 0.2, 12.5 ± 2.5 nm). SnTe@V showed the most pronounced cusp, largest α, and longest l(φ), indicating robust multi-channel WAL and stabilized, highly coherent topological surface states; the cover page does not render the coherence-length symbol, while the manuscript title page prints l(φ)