2 research outputs found
Interferometer for nanometric displacement sensing
Bakalaura darbÄ aplÅ«kotas interferometrisko metožu pielietoÅ”anas iespÄjas mazu
pÄrvietojumu mÄrÄ«Å”anai, paskaidroti dažÄda tipa interferometru darbÄ«bas principi, optisko
interferences signÄlu reÄistrÄÅ”anas un apstrÄdes metodes.
Darba rezultÄtÄ ar pieejamo aparatÅ«ru LU CFI SegnetoelektriÄu fizikas laboratorijÄ
nodemonstrÄts daudzstaru kompensÄta diferenciÄlÄ interferometra darbÄ«bas princips, parÄdot,
kÄ iespÄjams veikt mazu deformÄciju mÄrÄ«jumus ar augstu izÅ”ÄirÅ”anu. Izskaidrots divu optisko
detektoru (kvadratÅ«ras) reÄistrÄcijas metodes pielietojums joslu dalÄ«Å”anai un modulÄcijas
metodes pielietojums Äoti augstas izÅ”ÄirÅ”anas sasniegÅ”anai.
Ar darba rezultÄtiem ir parÄdÄ«ts, ka izveidotais interferometra prototips un piedÄvÄtÄs
datu reÄistrÄcijas un apstrÄdes metodes dod iespÄju ar nanometrisku precizitÄti veikt
segnetoelektrisku materiÄlu parauga virsmas pÄrvietojumu mÄrÄ«jumus.The work considers methods for small displacement sensing with nanometric
resolution using double pass differential interferometer. Various types of interferometers have
been discussed as well as methods of optical interference signal registration and processing.
As a result of this work the working principle of many-beam compensated differential
interferometer has been demonstrated in Ferroelectrics laboratory of UL ISSP. It has been
shown how to realize measurements of small deformations with high resolution and explained
how to use two optical detector (quadrature) registration for fringe subdivision. Also it has
been shown how to use modulation method to gain very high resolution.
Results have proved that this interferometer prototype and methods of data registration
and processing gives the ability to make nenometric precision measurements of surface
displacement of ferroelectric materials
Electromechanical Properties of Ferroelectric Relaxors
Segnetoelektriskie materiÄli tiek plaÅ”i pielietoti ļoti daudzÄs tehnoloÄ£ijÄs, un pÄdÄjÄs desmitgadÄs aktuÄla ir kļuvusi bezsvina segnetoelektriÄ·u pÄtÄ«Å”ana. NÄtrija bismuta titanÄts NaBiTiO3 (NBT) ir aktuÄls bezsvina segnetoelektrisks materiÄls, jo uzrÄda labas elektromehÄniskÄs Ä«paŔības. MaÄ£istra darba "Segnetoelektrisku relaksoru elektromehÄniskÄs Ä«paŔības" mÄrÄ·is ir veicinÄt LU Cietvielu fizikas institÅ«tÄ sÄkto jaunu NBT cieto Ŕķīdumu turpmÄku pÄtniecÄ«bu.
Darba gaitÄ ir izveidota eksperimentÄlÄ iekÄrta segnetoelektrisku materiÄlu paraugu deformÄcijas mÄrÄ«Å”anai atkarÄ«bÄ no pieliktÄ elektriskÄ lauka un paraugÄ inducÄtÄs polarizÄcijas. Ir izveidota datorprogramma, kas spÄj ar augstu izŔķirtspÄju izmÄrÄ«t interferences ainas pÄrvietoÅ”anos. Ir veikti pirmie mÄrÄ«jumi NBT ternÄrajiem cietajiem Ŕķīdumiem ar stroncija titanÄtu un svina titanÄtu.Ferroelectric materials have wide range applications in a lot of fields. Research on lead-free ferroelectrics has become actual in the last decades. Sodium bismuth titanate NaBiTiO3 (NBT) is an actual lead-free ferroelectric because it shows good electromechanical properties. The objective of Masters thesis "Electromechanical properties of ferroelectric relaxors" is to develop research on new NBT solid solutions that has been started in Institute of solid state physics (University of Latvia).
An experimental setup has been made in the course of this work to measure deformation of ferroelectric material samples in dependence of applied electric field and induced polarization. A computer program has been made that can measure interference pattern movement with high accuracy. First measurements of NBT ternary solid solutions with strontium titanate and lead titanate has been made