nkhani

PTC imatanthawuza chodabwitsa cha thermistor kapena zinthu zomwe zimakhala ndi kuwonjezereka kwakukulu kwa kukana ndi kutentha kwabwino pa kutentha kwina, komwe kungagwiritsidwe ntchito mwapadera ngati kachipangizo kakang'ono ka kutentha. Zomwe zili ndi thupi lopangidwa ndi sintered ndi BaTiO3, SrTiO3 kapena PbTiO3 monga gawo lalikulu, momwe ma oxides ochepa monga Nb, Ta, Bi, Sb, y, La ndi ma oxide ena amawonjezedwa kuti athe kuwongolera valence ya atomiki kuti apange. semiconducting. Izi semiconducting barium titanate ndi zipangizo zina nthawi zambiri amatchedwa semiconducting (zochuluka) zadothi; panthawi imodzimodziyo, ma oxides a manganese, chitsulo, mkuwa, chromium ndi zina zowonjezera zimawonjezedwa kuti awonjezere kutentha kwa mpweya wabwino.

PTC imatanthawuza chodabwitsa cha thermistor kapena zinthu zomwe zimakhala ndi kuwonjezereka kwakukulu kwa kukana ndi kutentha kwabwino pa kutentha kwina, komwe kungagwiritsidwe ntchito mwapadera ngati kachipangizo kakang'ono ka kutentha. Zomwe zili ndi thupi lopangidwa ndi sintered ndi BaTiO3, SrTiO3 kapena PbTiO3 monga gawo lalikulu, momwe ma oxides ochepa monga Nb, Ta, Bi, Sb, y, La ndi ma oxide ena amawonjezedwa kuti athe kuwongolera valence ya atomiki kuti apange. semiconducting. Izi semiconducting barium titanate ndi zipangizo zina nthawi zambiri amatchedwa semiconducting (zochuluka) zadothi; panthawi imodzimodziyo, ma oxides a manganese, chitsulo, mkuwa, chromium ndi zina zowonjezera zimawonjezeredwa kuonjezera kutentha kwa kutentha kwa kukana kwabwino. Titanate ya platinamu ndi yankho lake lolimba limapangidwa ndi mawonekedwe a ceramic wamba komanso kutentha kwambiri kuti apeze zida za thermistor zokhala ndi mawonekedwe abwino. Kutentha kwake ndi kutentha kwa Curie point kumasiyana malinga ndi momwe zimapangidwira komanso kutentha (makamaka kuzizira).
Makristasi a Barium titanate ndi a perovskite. Ndi ferroelectric material, ndipo barium titanate yoyera ndi insulating material. Pambuyo powonjezerapo zinthu zapadziko lapansi zomwe zimasokonekera ku barium titanate ndi chithandizo choyenera cha kutentha, resistivity imawonjezeka kwambiri ndi maulamuliro angapo a kukula mozungulira kutentha kwa Curie, zomwe zimapangitsa PTC zotsatira, zomwe zimagwirizana ndi ferroelectricity ya barium titanate crystals ndi zinthu zomwe zili pa kutentha kwa Curie. kusintha kwa gawo lapafupi. Ma ceramic titanate semiconductor ceramics ndi zida za polycrystalline zolumikizana pakati pa njere. Pamene semiconductor ceramic ifika kutentha kwina kapena voteji, malire a tirigu amasintha, zomwe zimapangitsa kusintha kwakukulu kwa kukana.
Mphamvu ya PTC ya barium titanate semiconductor ceramics imachokera ku malire a tirigu (malire a tirigu). Poyendetsa ma elekitironi, kulumikizana pakati pa tinthu tating'onoting'ono kumakhala ngati chotchinga chotheka. Pamene kutentha kuli kochepa, chifukwa cha zochita za magetsi mu titanate ya barium, ma electron amatha kudutsa mosavuta chotchinga chomwe chingathe, kotero kuti mtengo wotsutsa ndi wochepa. Kutentha kumadzuka pafupi ndi kutentha kwa Curie point (ie kutentha kwakukulu), gawo lamagetsi lamkati limawonongeka, zomwe sizingathandize kuyendetsa ma elekitironi kudutsa chotchinga chomwe chingathe. Izi zikufanana ndi kuwonjezeka kwa chotchinga chomwe chingatheke komanso kuwonjezeka kwadzidzidzi kwa kukana, zomwe zimabweretsa zotsatira za PTC. Zitsanzo zakuthupi za PTC zotsatira za barium titanate semiconductor ceramics zikuphatikizapo Haiwang surface barrier model, barium vacancy model ndi superposition barrier model ya Daniels et al. Apereka kufotokozera momveka bwino kwa zotsatira za PTC kuchokera kuzinthu zosiyanasiyana.