Transition between orbital orderings in YVO3

Area of Science:

• Solid-state physics
• Materials science
• Crystallography

Background:

• Yttrium Vanadium Oxide (YVO3) exhibits complex phase transitions influenced by orbital ordering and structural distortions.
• Jahn-Teller distortions are crucial in understanding the electronic and magnetic properties of transition metal oxides.

Purpose of the Study:

• To investigate the changes in vanadium d orbital occupation during the 77 K phase transition in YVO3.
• To determine the relationship between orbital ordering, magnetic ordering, and structural phase transitions in YVO3.
• To elucidate the mechanism driving the transition between different orbital ordering states.

Main Methods:

• Analysis of changes in the type of Jahn-Teller distortion at the 77 K phase transition.
• Tracking the persistence of orbital ordering above the magnetic ordering temperature (116 K) and up to the second structural phase transition (200 K).
• Investigating the role of octahedral tilting in mediating the transition between orbital orderings.

Main Results:

• A change in ordered occupation of vanadium d orbitals was observed at the 77 K phase transition in YVO3.
• The Jahn-Teller distortion type changes at 77 K, indicating a modification in orbital ordering.
• Orbital ordering remains intact above the magnetic ordering temperature (116 K) and persists until a structural phase transition at 200 K.
• Increasing octahedral tilting with decreasing temperature was identified as the cause for the transition between orbital orderings.

Conclusions:

• The 77 K phase transition in YVO3 is characterized by a significant change in vanadium d orbital ordering and Jahn-Teller distortion.
• Orbital ordering in YVO3 is robust, surviving magnetic ordering and extending to higher temperatures.
• Octahedral tilting is the key factor driving the observed transitions in orbital ordering within YVO3.