No peaks for Mn2+ ions were observed at 640–641 eV, which confirmed the formation of only the Mn4+ oxidation state with a d3 electronic configuration.
nˈoʊ pˈiːks fɔːɹ ˌɛmˈɛn tˈuː plˈʌs ˈaɪɑːnz wɜːɹ əbzˈɜːvd æt sˈɪkshˈʌndɹɪd fˈoːɹɾi sˈɪkshˈʌndɹɪd fˈoːɹɾi wˈʌn ˈiː vˈiː, wˌɪtʃ kənfˈɜːmd ðə fɔːɹmˈeɪʃən ʌv ˈoʊnli ðɪ ˌɛmˈɛn fˈoːɹ plˈʌs ˌɑːksɪdˈeɪʃən stˈeɪt wɪð ɐ dˈiː θɹˈiː ᵻlɛktɹˈɑːnɪk kənfˌɪɡjɚɹˈeɪʃən.