Investigation of the influence of VO2 formation on the structural morphology and magnetic properties in hydrothermally synthesized V6O13

Investigating the impact of hydrothermal duration on electronic magnetism, two distinct samples were synthesized: the V6O13 phase (S1) with 0.5 h of hydrothermal reaction, and the V6O13 and VO2 coexistent phase (S2) with 6 h of reaction. X-ray diffraction identified S1 as monoclinic C2/m, and S2 with a 4:1 ratio of V6O13 in P21/c space group VO2. Electron microscopy revealed rod-like V6O13 and spherical VO2. Both samples exhibited metal-insulator transitions, with the presence of VO2 in S2 elevating the metal-insulator phase transition onset temperature and widening the transition range. S1 exhibits antiferromagnetic ordering at low temperatures (TN 55 K) and follows the Curie-Weiss law above the metal-insulator transition temperature, while the behavior of S2 was modeled by a combination of Pauli and Curie-like paramagnetism, aligning well with experimental data. Small hysteresis loops in both samples suggested weak ferromagnetism; the linear loop of S1 indicated strong vanadium electron correlation, and the incomplete S-loop of S2 was attributed to the influence of VO2 on the electronic magnetism of V6O13.