Anomalous spontaneous-reduction of Mn⁷⁺/Mn⁴⁺to Mn²⁺and luminescence properties in Zn₂GeO₄:Mn

Abstract

The spontaneous-reduction of Mn7+or Mn4+to Mn2+with intense Mn2+-photoluminescence or afterglow luminescence has been first demonstrated in Zn2GeO4and A2BGeO4(A = Li, Na; B = Mg, Zn) synthesized by a high temperature solid state reaction method in air.

Deep‐red photoluminescence and long persistent luminescence in double perovstkite‐type La2MgGeO6:Mn4+

“…The complicated EPR peaks in the range of 3000–4000 G are observed, which consist of signals arising from manganese with different oxidation states. It has always been found Mn 2+ impurities exist in manganese doped phosphors because the decomposition or spontaneous reduction effect of Mn 4+ to Mn 2+ usually happens in the high temperature . Although the emission and excitation bands originated from Mn 2+ ions in LMG are hardly detected, the partially resolved hyperfine EPR signals of Mn 2+ ions are obviously observed at g of approximately 2.0.…”

An efficient synthetic strategy for uniform perovskite core–shell nanocubes NaMgF3:Mn2+,Yb3+@NaMgF3:Yb3+ with enhanced near infrared upconversion luminescence

“…, its emission wavelength can be easily tuned from green to deep red region depending strongly on the crystal field environment. [23][24][25] For instance, the tetrahedrally , we can further achieve NIR UC emission, which may find potential applications in highresolution bioimaging. 23 Moreover, as Mn 2+ ions own five unpaired d electrons, the Mn 2+ related nanocrystal can also be applied as an efficient T 1 magnetic resonance imaging (MRI) contrast agent, especially for Mn 2+ concentrated compound.…”

Long persistent and photo‐stimulated luminescence in Pr3+‐doped layered perovskite phosphor for optical data storage

“…To store the amounts of information, next‐generation supercapacity optical storage systems containing multiplexed information dimensions have drawn plenty of attention. Persistent luminescence (PersL) materials, well‐known for excellent photon storage ability under exposure of high excitation energy (e.g., ultraviolet light, visible light, electron beam, X‐ray), can meet the requirement of some optical storage devices . For PersL phenomena, it is generally accepted that the charge carriers (electron or holes) captured by traps is the main cause .…”