Approaching the free-ion limit in magnetically isotropic gadolinium(III) via borohydride ligands

Three new crystalline phases of the borohydride complex, [n-Bu4N][RE(BH4)(4)] (RE = Gd (1), Gd0.097Y0.903 (2) and Gd0.017Y0.983 (3)), were obtained in pure form and characterised using EPR spectroscopy and AC/DC magnetometry. In all 1-3, unusually slow field-induced magnetic relaxation was observed up to high temperatures, which above 10 K is dominated by power law thermal dependence identified as the two-phonon Raman process. Therefore, weak-field ligands such as borohydride seem to be the perfect candidates for triggering slow magnetic relaxation of magnetically isotropic gadolinium(iii) ions.

Automated summary

Three new crystalline phases of borohydride complex were obtained and characterized, showing unusually slow field-induced magnetic relaxation at high temperatures, which can be attributed to the thermal dependence of the two-phonon Raman process.