Time-resolved reflectivity and Raman studies of the interplay of electronic orders in Mo8 O23
Molybdenum suboxides
have been gaining attention lately due to their potential as charge storage materials and memory elements. In spite of increased interest in their functional properties, the phase diagrams, transient, and even equilibrium optical properties have not been systematically studied for many molybdenum suboxides, such as, for example, monoclinic semimetallic Mo8O23. This compound undergoes an incommensurate ordering transition at TIC ∼ 350 K, followed by a structural transition to commensurate order at TIC−C = 285 K, in addition, an enigmatic resistance maximum is observed at Tel ∼ 150 K, whose origin has so far proved elusive. In our combined polarized transient optical spectroscopy and Raman spectroscopy studies of the electronic relaxation dynamics and lattice vibrational modes in Mo8O23 single crystals we find evidences of the gapped state appearance below Tel that has so far eluded detection by structural analyses. The study was published in the paper Time-resolved reflectivity and Raman studies of the interplay of electronic orders in Mo8 O23 in Physical Review B.
Molibdenovim suboksidom je v zadnjem času namenjene vse več pozornosti zaradi njihovega potenciala kot snovi za shranjevanje naboja in spominske elemente. Kljub zanimanju za njihove funkcionalne lastnosti fazni diagrami, dinamične in celo ravnovesne optične lastnosti niso bili sistematično raziskani za večino molibdenovih suboksidov. Mednje spada tudi monoklinski polkovinski Mo8O23. Ta snov kaže prehod v inkomenzurabilno fazo pri TIC ∼ 350 K, ki mu sledi strukturni prehod v komenzurabilno fazo pri TIC−C = 285 K. Poleg tega je pri Tel ∼ 150 K opazen enigmatični maksimum električne upornosti, katerega izvor je doslej neznan. V naših optičnih raziskavah elektronske relaksacijske dinamike in vibracijskih načinov rešetke v kombinaciji z ramansko spektroskopijo monokristalov Mo8O23 smo našli dokaze o dodatnem faznem prehodu, katerega posledica je nastanek energijske reže pod Tel. Dodatnega faznega prehoda prejšnje, pretežno strukturne raziskave niso zaznale. Rezultati raziskave z naslovom Time-resolved reflectivity and Raman studies of the interplay of electronic orders in Mo8 O23 so bili objavljeni v reviji Physical Review B.