Temperature determination based on luminescence of rare-earth and transition metal doped powders

Abstract

Osnovni cilj ove doktorske disertacije je beskontaktno određivanje temperature korišćenjem luminescentne spektroskopije. Senzori temperature mogu biti najrazličitiji materijali, ali svi moraju imati zajedničko da im se neki fizički parametar manje ili više menja sa temperaturom. Za praktičnu primenu najznačajniji opseg temperatura je oko telesne i sobne temperature (20-50 °C) dok su za industriju interesantnije povišene temperature jer su radne temperature postrojenja dosta visoke (preko 500 °C). U okviru ove doktorske disertacije sintetisani su različiti materijali uz upotrebu dobro poznatih metoda sinteze sa definisanim temperaturama i dužinama žarenja. Seskvioksidi su sintetisani metodom polimerno-kompleksnog rastvora, litijum metatitanati su sintetisani jednostavnom metodom u čvrstoj fazi i magnezijum ortotitanati su sintetisani Pećini metodom. Materijali su dopirani jonima retkih zemalja i prelaznih metala. Svi uzorci su prvo okarakterisani XRD analizom kako bi se utvrdila čista faza i struktura uzorka. Najznačajniji deo ovih istraživanja je ispitivanje spektroskopskih karakteristika i njihovo ponašanje sa promenom temperature. Pokazano je da emisioni spektri i vremena života sintetisanih prahova zavise od temperature u širokom temperaturskom opsegu od 10-350 K. Visoke vrednosti relativne osetljivosti i temperaturske rezolucije koje su dobijene u okviru izrade ove doktorske disertacije pokazuju da ovi materijali mogu vrlo uspešno da se koriste kao senzori temperature.The basic objective of this PhD thesis was non-contact determination of temperature using luminescence spectroscopy. The temperature sensors could be a different type of material, but all must have one thing in common - one parameter is more or less changing with the temperature. The most important temperature range for practical application is around physiological and room temperature (20-50°C). Higher temperatures might be of interest to the industry because operating temperature of the plant is very high (above 500°C). In this study different type of materials were synthesized using well-known synthesis methods at optimum temperatures. Sesquioxide was synthesized using a polymer-complex method, lithium metatitanate using solid-state method and magnesium orthotitanate was synthesized using Peccini-type of synthesis. Rare earth and transition metal ions were used as a dopant. All samples were first investigated using XRD analysis to confirm pure phase and crystalline structure. The most important part of this study was investigation of spectroscopic characteristic and their behavior with changes of temperature. It was shown that emission spectra and lifetime of the synthesized powders are temperature-dependent in large temperature range (from 10-350K). High values of relative sensitivity and temperature resolution shown in this thesis makes these materials suitable candidates as a temperature sonsors