TY  - JOUR
AU  - Mueller, Michael P.
AU  - Gunkel, Felix
AU  - Hoffmann-Eifert, Susanne
AU  - De Souza, Roger A.
TI  - The importance of singly charged oxygen vacancies for electrical conduction in monoclinic HfO 2
JO  - Journal of applied physics
VL  - 129
IS  - 2
SN  - 1089-7550
CY  - Melville, NY
PB  - American Inst. of Physics
M1  - FZJ-2021-00192
SP  - 025104 -
PY  - 2021
AB  - The point-defect structure of monoclinic HfO2 (m-HfO2) was studied by means of equilibrium electrical conductance measurements as a function of temperature 1050≤T/K≤1200 and oxygen partial pressure −20≤log(pO2/bar)≤−2. The total conductivity σ displayed similar behavior at each temperature examined. In oxidizing conditions (pO2≥10−7bar), the total conductivity increased with increasing oxygen partial pressure and was assigned to hole conduction. Around 10−10 bar, a region of almost constant conductivity was found; this is ascribed to ionic conduction by means of doubly charged oxygen vacancies. In reducing conditions (pO2≤10−16bar), the total conductivity surprisingly decreased with decreasing oxygen partial pressure. Defect-chemical modeling indicates that this behavior is consistent with the conversion of mobile doubly charged oxygen vacancies into less mobile singly charged vacancies by electron trapping. Point-defect concentrations at the oxygen partial pressures relevant to resistive switching devices are predicted and discussed.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000608037800004
DO  - DOI:10.1063/5.0036024
UR  - https://juser.fz-juelich.de/record/889300
ER  -