Dr Chakrabarty keskendub oma 24 kuulise MOBJD projekti jooksul tahkiste sünteesikeskuse ülesehitamisele ja käivitamisele KBFIs ja kasvatab ning karakteriseerib (XRD, PPMS, NMR etc) seal mitmeid uudseid kvantmagneetikuid. Teostatavad eksperimendid võimaldavad otsest võrdlust KBFIs loodud DFT+U põhiste magnetmudelitega. Dr Chakrabarty teostas oma PhD töö IIT Bombay materjaliuuringute Prof. Mahajani töörühmas Indias ja omab juba ka järeldoktorikogemust Iisrealist. Kuna KBFIs kui ka Eestis laiemalt mono- ja polükristalsete oksiidide sünteesi ekspertiis puudub, on taotleja taust ja oskused väga kohased Eesti sellise kaasaegse materjaliteaduse suuna arendamiseks. Dr. Raivo Stern, KBFI juhtivteadur, juhendab teadustegevust; projekt täiendab teaduse tippkeskuse “Emerging orders in quantum and nanomaterials” (EQUITANT) tegevusi ja sobitub tööstuskoostööga tahkete oksiidide kasutamiseks (EU project HELTSTACK (FP7-PEOPLE-2013-IAPP)) ning KBFI tegevustega doktorikoolis FMTDK.
During his 24 months MOBJD stay, Tanmoy Chakrabarty will focus on setting up a solid oxide synthesis facility at NICPB and synthesize and characterize (XRD, PPMS, NMR etc) several novel quantum systems. Experiments on new materials will enable direct comparison with the simulations of the DFT+U based microscopic magnetic models at NICPB. Dr Chakrabarty performed his Ph. D. study at the IIT, Bombay, India, in the materials research group of Prof. Mahajan. Since the NICPB is presently lacking expertise in solid oxide mono- and polycrystalline synthesis, the applicant's experience will be helpful to advance the Estonian scientific potential on this vibrant field of materials science. Dr. Raivo Stern, a researcher professor at NICPB will supervise the proposed research; the project will complement the activities of the Centre of Excellence “Emerging orders in quantum and nanomaterials” (EQUITANT) and the industrial solid oxide application (EU project HELTSTACK (FP7-PEOPLE-2013-IAPP)).
During my 24 months MOBJD stay I have accomplished the following targets, however some portions of my project remained partially fulfilled. (1) We have finished the project on a novel S=1/2 uniform spin chain compound Bi6V3O16 by studying its NMR, magnetization and heat capacity properties. (2) During this project we have also studied the NMR line structure of the nonmagnetic analogue of this family Bi4V2O11 which helped us significantly in explaining the structure of the spin chain compound Bi6V3O16 and choosing the proper magnetic model applicable to explain its properties. (3) This is one of the few S=1/2 vanadium-based uniform spin chain system found experimentally where the spin- chain coupling (J/kB) is as high as 100 K. (4) Very recently this work has been published in a peer-reviewed journal (Phys Rev B). (5) We have also studied another low dimensional compound InCuPO5 via bulk and NMR measurement however to know the real picture inside the system we need to study it in its single crystalline form. (6) I have attempted to prepare another novel low dimensional S=1/2 system, however I could not prepare the pristine sample. This requires few more attempts to find the ideal condition for synthesis. Overall the output of the project will contribute in the physics of low dimensional magnetism. Our experiments also reveal the power of the magic angle spinning NMR (MASNMR) experiments over the static NMR and bulk probes, to extract the local magnetic (microscopic) properties of a system. This is the part of the project which makes me really happy as this experimental probe was only present in NICPB in Estonia and we were able to use it in a meaningful way to science.