Understanding the key factor controlling phase transitions of correlated oxides by chemical doping is becoming of fundamental and technological interest. Here, we report vanadium chain symmetry as an effective means of mediating the structural phase transition (SPT) temperature in hydrothermal Cr-doped VO2. In-situ X-ray absorption fine structure spectroscopy unveils that high structural symmetry with equidistant 2.93 angstrom VV zigzag chains, along with the dimerized VV straight chain induced by Cr-doping, can stabilize VO2 at elevated temperature, thus raising the critical temperature of the VO2 phase transition. The Cr-doped VO2 system exhibited a SPT process involving lattice expansion, accompanied by VV chain reconstruction into the rutile phase. These findings provide novel insights and guidance in chemically tailoring the phase transition of VO2.
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