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Rb 2 CaCu 6 (PO 4 ) 4 O 2 , a novel oxophosphate with a shchurovskyite‐type topology: synthesis, structure, magnetic properties and crystal chemistry of rubidium copper phosphates
Author(s) -
Aksenov Sergey M.,
Borovikova Elena Yu.,
Mironov Vladimir S.,
Yamnova Natalia A.,
Volkov Anatoly S.,
Ksenofontov Dmitry A.,
Gurbanova Olga A.,
Dimitrova Olga V.,
Deyneko Dina V.,
Zvereva Elena A.,
Maximova Olga V.,
Krivovichev Sergey V.,
Burns Peter C.,
Vasiliev Alexander N.
Publication year - 2019
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520619008527
Subject(s) - antiferromagnetism , monoclinic crystal system , crystallography , magnetization , crystal structure , hydrothermal synthesis , chemistry , ferromagnetism , magnetic susceptibility , hydrothermal circulation , single crystal , type (biology) , materials science , physics , condensed matter physics , magnetic field , geology , paleontology , quantum mechanics , seismology
Single crystals of Rb 2 CaCu 6 (PO 4 ) 4 O 2 were synthesized by a hydrothermal method in the multicomponent system CuCl 2 –Ca(OH) 2 –RbCl–B 2 O 3 –Rb 3 PO 4 . The synthesis was carried out in the temperature range from 690 to 700 K and at the general pressure of 480–500 atm [1 atm = 101.325 kPa] from the mixture in the molar ratio 2CuO:CaO:Rb 2 O:B 2 O 3 :P 2 O 5 . The crystals studied by single‐crystal X‐ray analysis were found to be monoclinic, space group C 2, a = 16.8913 (4), b = 5.6406 (1), c = 8.3591 (3) Å, β = 93.919 (3)°, V = 794.57 (4) Å 3 . The crystal structure of Rb 2 CaCu 6 (PO 4 ) 4 O 2 is similar to that of shchurovskyite and dmisokolovite and is based upon a heteropolyhedral open framework formed by polar layers of copper polyhedra linked via isolated PO 4 tetrahedra. The presence of well‐isolated 2D heteropolyhedral layers in the title compound suggests low‐dimensional magnetic behavior which is masked, however, by the fierce competition between multiple ferromagnetic and antiferromagnetic exchange interactions. At T C = 25 K, Rb 2 CaCu 6 (PO 4 ) 4 O 2 reaches a magnetically ordered state with large residual magnetization.