Hybrid Layered Double Perovskite Halides of Transition Metals

Hybrid layered double perovskite (HLDP) halides comprise hexacoordinated 1+ and 3+ metals in the octahedral sites within a perovskite layer and organic amine cations between the layers. Progress on such materials has hitherto been limited to compounds containing main group 3+ ions isoelectronic with Pb-II (such as Sb-III and Bi-III).( )Here, we report eight HLDP halides from the A(2)M(I)M(III)X(s) family, where A = para-phenylenediammonium (PPDA), 1,4-butanediammonium (1,4-BDA), or 1,3-propanediammonium (1,3-PDA); M-I = Cu or Ag; M-III = Ru or Mo; X = Cl or Br. The optical band gaps, which lie in the range 1.55 to 2.05 eV, are tunable according to the layer composition, but are largely independent of the spacer. Magnetic measurements carried out for (PPDA)(2)(AgRuCl8)-Ru-I-Cl-III and (PPDA)(2)(AgMoCl8)-Mo-I-Cl-III show no obvious evidence of a magnetic ordering transition. 'While the t 2g 3 Mo m compound displays Curie-Weiss behavior for a spin-only d(3) ion, the t(2g)(5) Ru(III )compound displays marked deviations from the Kotani theory.

Automated summary

This study reports a new type of hybrid layered double perovskite (HLDP) halides whose optical band gaps can be tuned by the layer composition, and the magnetic behavior is related to the material's composition.