Alates kõrgtemperatuurse ülijuhtivuse probleemi lahenduste otsimisest on mitmesuguste magnetiliste korrastuste uurimine kupraatides, vanadaatides ja sarnastes ühendites saanud tahke keha füüsika tähtsaks uurimisvaldkonnaks. Spinn-vedelikud, frustreeritud spinn-korrad, orbitaalne korrastumine on mõned märksõnad, mis on paljude eksperimentaatorite ja tahke keha füüsika teoreetikute laual.
Tuumamagnetresonants (nuclear magnetic resonance NMR, eesti keeles ka TMR) on üks peamisi spektroskoopilisi tehnikaid, mida kaasajal kasutatakse laialdaselt nii keemias, bioloogias kui ka füüsikas. Selle tugevus seisneb unikaalses võimes saada mitmekülgset informatsiooni uuritava aine lokaalse struktuuri ja dünaamika kohta. NMR-I eksperimentidest saadav informatsioon on väärtuslik täiendus difraktsioonimeetoditega saadud teadmistele aine struktuuri kaugkorrapära kohta. Eriti mõttekad on NMR-i mõõtmised ainetes, milles kaugkorrapära puudub, ainetes, mille omadused määrab väike hulk lisandeid, või ainetes, mille omadused määratakse eeskätt lähikorra iseärasustega nagu enamikus magnetilistes materjalides.
Allenspach, S., Puphal, P., Link, J., Heinmaa, I., Pomjakushina, E., Krellner, C., Lass, J., Tucker, G. S., Niedermayer, C., Imajo, S., Kohama, Y., Kindo, K., Krämer, S., Horvatic, M., Jaime, M., Madsen, A., Mira, A., Laflorencie, N., Mila, F., Normand, B., Rüegg, C., Stern, R., Weickert, F. 2021. Revealing three- dimensional quantum criticality by Sr substitution in Han purple. Physical Review Research, 3(2), 023177.
https://doi.org/10.1103/PhysRevResearch.3.023177
Arčon, D., Heinmaa, I., Stern, R. 2018. Low-temperature NMR: Techniques and Applications. – Hodgkinson, P. (ed). Modern Methods in Solid state NMR: A Practitioner’s Guide. New Developments in NMR, 15, 233–261.
https://doi.org/10.1039/9781788010467-00231
Bounds, R. W., Pavarini, E., Paolella, M., Young, E., Heinmaa, I., Stern, R., Carravetta, M. 2018. Study of B-11 and C-13 NMR on doped MgB2 in the normal and in the superconducting state. Physical Review B, 97, 014509 (9).
https://doi.org/10.1103/PhysRevB.97.014509
Chakrabarty, T., Heinmaa, I., Verchenko, V. Yu., Paulose, P. L., Stern, R. 2019. NMR, magnetization, and heat capacity studies of the uniform spin-1/2 chain compound Bi6V3O16. Physical Review B, 100, 09443.
https://doi.org/10.1103/PhysRevB.100.094431
Chakrabarty, T., Heinmaa, I., Koteswararao, B., Stern, R. 2021. Contradiction of one-dimensional magnetism in InCuPO5 from MAS-NMR experiments. – National Conference on Physics and Chemistry of Materials (NCPCM 2020), AIP Conference Proceedings, 2369, 020050.
https://doi.org/10.1063/5.0061113
Jaime, M., Correa, V. F., Harrison, N., Batista, C. D., Kawashima, N., Kazuma, Y., Jorge, G. A., Stern, R., Heinmaa, I., Zvyagin, S. A., Sasago, Y., Uchino- kura, K. 2004. Magnetic-field-induced condensation of triplons in Han purple pigment BaCuSi2O6. Physical Review Letters, 93, 087203.
https://doi.org/10.1103/PhysRevLett.93.087203
Khalaniya, R. A., Verchenko, V. Yu., Wei, Z., Dikarev, E. V., Heinmaa, I., Stern, R., Jesche, A., Tsirlin, A. A., Shevelkov, A. V. 2019. From Fe32+δGe35–xPx to Fe32+δGe35–x–yPxAsy: Fine geometry optimization in new intergrowth struc- tures. Journal of Alloys and Compounds, 779, 229–236.
https://doi.org/10.1016/j.jallcom.2018.11.208
Opherden, D., Nizar, N., Richardson, K., Monroe, J. C., Turnbull, M. M., Pol- son, M., Vela, S., Blackmore, W. J. A., Goddard, P. A., Singleton, J., Choi, E. S., Xiao, F., Williams, R. C., Lancaster, T., Pratt, F. L., Blundell, S. J., Skourski, Y., Uhlarz, M., Ponomaryov, A. N., Zvyagin, S. A., Wosnitza, J., Baenitz, M., Hein- maa, I., Stern, R., Kühne, H., Landee, C. P. 2020. Extremely well-isolated two- dimensional spin-1/2 antiferromagnetic Heisenberg layers with small exchange coupling in the molecular-based magnet CuPOF. Physical Review B, 102, 064431.
https://doi.org/10.1103/PhysRevB.102.064431
Opherden, D., Bärtl, F., Yamamoto, Sh., Zhang, Z. T., Luther, S., Molatta, S., Wosnitza, J., Baenitz, M., Heinmaa, I., Stern, R., Landee, C. P., Kühne, H. 2021. Freezing of molecular motion in a paramagnetic crystal studied by 31P NMR. Physical Review B, 103, 014428.
https://doi.org/10.1103/PhysRevB.103.014428
Pasco, C. M., Trump, B. A., Tran, Thao T., Kelly, Z. A., Hoffmann, C., Hein- maa, I., Stern, R., McQueen, T. M. 2018. Single-crystal growth of Cu4(OH)6BrF and universal behavior in quantum spin liquid candidates synthetic barlowite and herbertsmithite. Physical Review Materials, 2, 044406-1-9.
https://doi.org/10.1103/PhysRevMaterials.2.044406
Puphal, P., Sheptyakov, D., van Well, N., Postulka, L., Heinmaa, I., Ritter, F., Assmus, W., Wolf, B., Lang, M., Jeschke, H. O., Valentí, R., Stern, R., Rüegg, C., Krellner, C. 2016. Stabilization of the tetragonal structure in (Ba1−xSrx)CuSi2O6. Physical Review B, 93, 174121.
https://doi.org/10.1103/PhysRevB.93.174121
Rästa, R., Heinmaa, I., Kimura, K., Kimura, T., Stern, R. 2020. Magnetic struc- ture of the square cupola compound Ba(TiO)Cu4(PO4)4. Physical Review B, 101, 054417.
https://doi.org/10.1103/PhysRevB.101.054417
Silverstein, H. J., Sinclair, R., Sharma, A., Qiu, Y., Heinmaa, I., Leitmäe, A., Wiebe, C. R., Stern, R., Zhou, H. 2018. Naturally tuned quantum critical point in the S = 1 kagomé YCa3(VO)3(BO3)4. Physical Review Materials, 2, 044006.
https://doi.org/10.1103/PhysRevMaterials.2.044006
