Diffuziya shchelochnogo metalla v ferritnykh sistemakh

Vyyasnen mekhanizm tverdofaznogo vzaimodeistviya monoferrita kaliya s gematitom. Opredelena rol' oksida zheleza kak matritsy dlya sozdaniya dal'neishei struktury katalizatora. V protsesse ehksperimenta gotovilis' tabletirovannye obraztsy monoferrita kaliya i gematita. Tabletki pomeshchalis' v spetsial'nyi zazhim i podvergalis' termoobrabotke. Metodom iskusstvennoi metki byl issledovan mekhanizm tverdofaznogo vzaimodeistviya v sisteme KFeO2-Fe2O3. Dlya otsenki sootnosheniya produktov tverdofaznogo vzaimodeistviya monoferrita kaliya s gematitom ispol'zovali parametry q, rasschityvaemye po dannym rentgenografii. Predstavlena stolbchataya diagramma parametrov q[β"(0111)], q[β(017)] i q[Fe2O3(110)] v zavisimosti ot glubiny proniknoveniya kaliya v ob"em gematita. Analiz struktur gematita i poliferritov kaliya pozvolyaet predpolozhit', chto iony shchelochnogo metalla diffundiruyut v reshetku gematita. V obrazovavshemsya poliferrite dvizhenie kationov prodolzhaetsya mezhdu blokami sostava {Fe11O17}. Iony K+ zanimayut pravil'nye pozitsii v reshetke obrazovavshegosya poliferrita. Blizhe k granitse soprikosnoveniya tabletok raspolagaetsya sloi, bogatyi β″-poliferritom kaliya. Po mere udaleniya ot granitsy kontakta tabletok obrazuyutsya poliferrity shchelochnogo metalla so strukturami β"-glinozema i β-glinozema. Po mere udaleniya ot granitsy soprikosnoveniya tabletok soderzhanie β″-poliferrita umen'shaetsya s vozrastanie doli β- fazy. Obrazuyushchiesya poliferrity po svoei suti yavlyayutsya tverdymi ehlektrolitami, sposobnymi obespechivat' transport ionov shchelochnogo metall po opredelennym kanalam v strukture poliferrita. Privedena zavisimost' faktora f(β″), opisyvayushchego sootnoshenie β- i β″-faz v produktakh ferritoobrazovaniya, ot stepeni prevrashcheniya monoferrita kaliya v poliferrity pri termoobrabotke smesei KFeO2+2Fe2O3 pri temperature 1150 K. Pri uvelichenii stepeni prevrashcheniya f(β″) umen'shaetsya, dostigaya opredelennogo sootnosheniya β- i β″-poliferritov. Stabilizatsiya v ehtom sluchae bystree vsego dostigaetsya za schet ehnergii kogerentnogo srastaniya β- i β″-faz.