Influence of La doping on the magnetic properties of the two-dimensional spin-gapped system SrCu$_2$(BO$_3$)$_2$

Šibav, Lia (avtor), Knaflič, Tilen (avtor), King, Graham (avtor), Jagličić, Zvonko (avtor), Koblar, Maja (avtor), Povarov, Kirill (avtor), Zvyagin, Sergei (avtor), Arčon, Denis (avtor), Dragomir, Mirela (avtor)

Doping of the two-dimensional dimer antiferromagnet SrCu$_2$(BO$_3$)$_2$ has long been proposed as a potential route toward realizing resonating valence bond superconductivity in this system; however, experimental progress has remained limited. This study explores the effects of La doping on the ground state of SrCu$_2$(BO$_3$)$_2$ and reports the first flux growth of Sr$_{1−x}$La$_x$Cu$_2$(BO$_3$)$_2$ single crystals with nominal doping levels up to x = 0.15. Powder X-ray diffraction and energy-dispersive X-ray spectroscopy confirm the successful incorporation of La on the Sr sites within the same tetragonal I$\overline 4$2m structure, although the effective doping was found to be <50% of the nominal concentration. La doping induces systematic changes in the magnetic properties of SrCu$_2$(BO$_3$)$_2$, with a reduction of the effective spin gap from 28.2 K for the undoped sample to 20.3 K for x = 0.15, as determined from the low-temperature magnetic susceptibility. The X-band electron spin resonance measurements reveal the emergence of unpaired Cu$^{2+}$ spins, which develop antiferromagnetic correlations below ∼5.5 K. These findings corroborate the breaking of the local spin dimers in SrCu$_2$(BO$_3$)$_2$ induced by La doping. No superconductivity is observed across the entire doping range studied.

• Jezik: Angleški jezik
• Ključne besede: antiferromagnets, doping, crystal structure, electron paramagnetic resonance spectroscopy, quantum mechanics, thermodynamic properties
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FGG - Fakulteta za gradbeništvo in geodezijo ; FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: Str. 291–302
• Številčenje: Vol. 65, iss. 1
• PID: 20.500.12556/RUL-177911
• UDK: 621.7+621.9
• ISSN pri članku: 1520-510X
• DOI: 10.1021/acs.inorgchem.5c04249
• COBISS.SI-ID: 264142851
• Datum objave v RUL: 13.01.2026

Gradivo je del revije

• Naslov: Inorganic chemistry
• Skrajšan naslov: Inorg. chem.
• Založnik: American Chemical Society
• ISSN: 1520-510X
• COBISS.SI-ID: 512805401

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: antiferomagneti, dopiranje, antiferomagnetizem, superprevodnost, lantan, magnetne lastnosti