%0 Journal Article
%A Mueller, Michael P.
%A Gunkel, Felix
%A Hoffmann-Eifert, Susanne
%A De Souza, Roger A.
%T The importance of singly charged oxygen vacancies for electrical conduction in monoclinic HfO 2
%J Journal of applied physics
%V 129
%N 2
%@ 1089-7550
%C Melville, NY
%I American Inst. of Physics
%M FZJ-2021-00192
%P 025104 -
%D 2021
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000608037800004
%R 10.1063/5.0036024
%U https://juser.fz-juelich.de/record/889300