Prosto mesto mladega raziskovalca na področju Tehnološko usmerjena fizika

Open position for a PhD student in Technology driven physics

1. V Centru za magnetne meritve (CMag) imamo merske sisteme, ki omogočajo celovito merjenje magnetnih, toplotnih in električnih transportnih lastnosti snovi v temperaturnem območju od 300 mK do 400 K. Meritve lastnosti snovi segajo od osnovnih raziskav snovi na nivoju gradnikov snovi do raziskav novih molekularnih struktur, ki nudijo novo uporabo v kemični, farmacevtski, metalurški in elektronski industriji.
   
   V letošnjem letu bomo postavili dodatni merski sistem, ki nam bo omogočal tudi raziskavo feroelektričnih lastnosti snovi in v povezavi z magnetnim sistemom tudi raziskavo vpliva magnetnega polja na feroelektrične lastnosti multiferoikov. To so snovi, ki kažejo tako feromagnetne kot feroelektrične lastnosti.
   
   Okvirni program dela MR na tem področju bi zajemal predvsem eksperimentalno delo na tem novem merskem sistemu in raziskavo multiferoičnih materialov.
   
   Pričakovana izobrazba: magisterij iz fizike ali elektrotehnike.


2. V laboratoriju za merjenje jedrske kvadrupolne resonance (JKR) na IMFM, imamo dva komercialna spektroskopska sistema za merjenje JKR v trdnih snoveh in računalniško vodeno robotsko roko za premikanje trajnih magnetov in vzorcev. Razvili smo tudi lastni prenosni spektrometer, ki ga lahko uporabljamo tudi izven laboratorija.
   
   JKR je nedestruktivna, brezkontaktna radiofrekvečna (RF) spektroskopska metoda, ki je podobna bolj znani jedrski magnetni resonanci (JMR). Za razliko od JMR, lahko JKR prehode v jedrih zaznamo brez uporabe zunanjega magnetnega polja ("Zero Field MR"). JKR temelji na električni interakciji med jedrom z električnim kvadrupolnim momentom (spin 1 ali več) in notranjim gradientom električnega polja (GEP), ki ga povzročajo okoliški elektroni v kristalni mreži. GEP na mestu jedra v dani sestavini določajo predvsem valenčni elektroni, ki sodelujejo v vezeh z ostalimi sosednjimi jedri, zato je frekvenca, pri kateri se pojavi JKR prehod, točno določena za to substanco. JKR lahko merimo na trdnih vzorcih v svoji začetni obliki (praški, granulati, tablete ipd.), ki se lahko uporabijo celo v originalni embalaži, če le-ta ni v celoti kovinska. Za uporabo JKR so zanimiva jedra dušika ¹⁴N (spin 1), saj se dušik nahaja v velikem številu tako organskih kot anorganskih spojin. Metoda je uporabna na področju farmacevtskih raziskav, pri nadzoru kvalitete proizvodnje in pri zaznavi prepovedanih snovi (eksplozivi, ponarejena zdravila).
   
   Okvirni program dela na tem področju bi zajemal optimizacijo merskih tuljav in raziskave različnih snovi tako na področju prepovedanih snovi (eksplozivi, narkotiki, ponarejena zdravila) kot na področju nadzora aktivnih snovi, ki se uporabljajo v farmacevtskih izdelkih.
   
   Pričakovana izobrazba: magisterij iz fizike ali elektrotehnike ali farmacije.


3. Ukvarjamo se tudi s področjem biomagnetizma. To so magnetna polja, ki izvirajo iz delovanja bioloških organizmov. Pri ljudeh in živalih so glavni izvor električni tokovi, ki spremljajo krčenje mišic (npr. srca, ki je najmočnejši izvor), prenos signalov po živčnih vlaknih in delovanje možganov. Žal so ta polja izredno šibka, zato zahtevajo drago mersko opremo, ki jo pri nas nimamo. Sodelujemo pa že skoraj 40 let s Physikalisch-Technische Bundesanstalt (PTB) Institutom v Berlinu, kjer imajo eno najboljših magnetno zaščitenih sob na svetu in več merskih sistemov, ki omogočajo meritve teh signalov. V preteklosti smo načrtovali in uspešno izvedli že več meritev. Trenutno se v okviru bilateralnega projekta z Nemčijo ukvarjamo z aplikacijo novih magneto-optičnih detektorjev za zaznavo magnetoencefalograskih (MEG) signalov, ki izvirajo iz odziva možganov na slušno in motorično vzdraženje.
   
   Naše delo na tem področju je predvsem teoretično-računsko, kjer na podlagi računalnikih modelov poskušamo lokalizirati tokovne izvore, ki generirajo izmerjeno polje. Dobra stvar pri teh modelih je, da se dajo uporabiti tudi pri obravnavi elektoencefalograskih (EEG) podatkov, to so meritve električnih potencialov na površini glave, saj ti izvirajo iz istih tokovnih izvorov kot MEG podatki. EEG podatke za epileptične bolnike lahko dobimo na Nevrološki kliniki UKC v Ljubljani.
   
   Okvirni program dela na tem področju bi zajemal nekaj eksperimentalnega dela na Institutu PTB v Berlinu in zahtevno računalniško modeliranje, ki vključuje tako realistično geometrijo glave in tokovnih izvorov kot reševanje inverznega problema, kjer iz izmerjenih podatkov (MEG/EEG) določimo izvor.
   
   Pričakovana izobrazba: magisterij iz fizike ali računalništva ali elektrotehnike.


4. Gradbena fizika na področju ne destruktivnih preizkušanj in/ali aplikaciji novih senzorskih tehnogij v gradbeništvu.
   
   Pričakovana izobrazba: magisterij iz gradbeništva.
   

1. In the Center for Magnetic measurements (CMag) we have measurement systems for the complete measurement of the magnetic, thermal and electrical transport properties of substances in the temperature range from 300 mK to 400 K. Studies span from basic research of materials up to research of new molecular structures that offer a new use in the chemical, pharmaceutical, metallurgical and electronic industries.
   
   This year we will set up an additional measurement system which will enable investigation of ferroelectric properties of the substance and, in connection with the magnetic system, also study of the influence of the magnetic field on the ferroelectric properties of multiferoics. These are substances that exhibit both ferromagnetic and ferroelectric properties.
   
   The expected work program of the PhD student in this field would mainly cover experimental work on this new measurement system and the research of multiferoic materials.
   
   Expected qualification: Msc in Physics or Electrical Engineering.


2. We have also nuclear quadruple resonance (NQR) laboratory, where we have two commercial spectroscopic systems for measuring NQR in solids and a computer-controlled robotic arm for moving permanent magnets and samples. We have also developed our own portable spectrometer, which can also be used outside the laboratory.
   
   NQR is a non-destructive, non-contact radiofrequency (RF) spectroscopic method, similar to a more familiar nuclear magnetic resonance (NMR). Unlike NMR, NQR transitions in nuclei can be detected without the use of an external magnetic field ("Zero Field MR"). NQR is based on the electrical interaction between the nuclei with an electric quadrupole moment (spin 1 or more) and an internal electric field gradient (EFG) generated by the surrounding electrons in the crystal cage. EFG at the site of the nucleus in a given component is primarily determined by valence electrons that are involved in bonds with other adjacent nuclei, so the frequency at which the NQR transition occurs is unique for each substance. The NQR can be measured on solid samples in its initial form (powders, granulates, tablets, etc.) that can be used even in original packaging if it is not completely metallic. ¹⁴N nuclei (spin 1) are interesting for the NQR application because nitrogen is found in a large number of organic and inorganic compounds. The method is applicable in the field of pharmaceutical research, in the control of production quality and in the detection of illicit substances (explosives, narcotics, fortified medicines).
   
   The expected work program in this field would cover the optimization of the measurement coils for detection of various illicit substances, and the research and control of active substances in pharmaceutical products.
   
   Expected qualification: Msc in Physics or Electrical Engineering or Pharmacy.


3. We are also working in the field of biomagnetism. These magnetic fields originate from the biological organisms. In humans and animals, the main sources are electric currents, which accompany muscle contraction (e.g., the heart, which is the strongest source), the transmission of signals by nerve fibers and the functioning of the brain. Unfortunately, these fields are extremely weak, so they require expensive equipment that we do not have. We have been cooperated for nearly 40 years with the Physikalisch-Technische Bundesanstalt (PTB) Institute in Berlin, where they have one of the best magnetically-protected room in the world and several measurement systems that allow measurement of these signals. In the past, we have already planned and successfully carried out several measurements. In the framework of a bilateral project with Germany, we are currently involved in the application of new magneto-optical detectors for the detection of magnetoencephalographic (MEG) signals originating from the brain's response to the auditory and motor nerve system stimulations.
   
   Our work in this field is mainly theoretical and computer modeling, where on the base of models we try to localize the current sources that generate the measured field. These models can be also used to analyze the electroencephalographic (EEG) data, where the electrical potentials on the surface of the head, which originate from the same current sources as MEG data, are measured. EEG data for epileptic patients can be obtained at the Neurological Clinic UKC in Ljubljana.
   
   The expected work program in this field would cover some experimental work at the PTB Institute in Berlin and advanced computer modeling, which includes both the realistic geometry of the head and current sources, and the solution of the inverse problem, where the source is determined from the measured data (MEG/EEG).
   
   Expected qualification: Msc in Physics or Computer sciences or Electrical Engineering.
   


4. Building Physics, specifically in the field of Non Destructive testing and/or Application of new sensor technologies in civil engineering.
   
   Expected qualification: Msc in Civil Engineering.
   

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