Luminescence properties of “relatively” trap-free crystals of anhydrous salts containing divalent manganese

Cooperative Near‐IR to Visible Photon Upconversion in Yb3+‐Doped MnCl2 and MnBr2: Comparison with a Series of Yb3+‐Doped Mn2+ Halides

“…At 150 K its intensity is reduced to less than 10 % of the 12 K value for both MnCl 2 :Yb 3 + and MnBr 2 :Yb 3 + . This is attributed to the onset of efficient energy migration to killer traps within the Mn 2 + system above 100 K [23] and an additional loss channel via the Yb T 1g luminescence was estimated [21] from the 4 T 1g absorption intensity as t rad = 2.8 ms, which is in perfect agreement with measured lifetime of t = 2.8 ms. This result indicates that the measured lifetime is in fact radiative at 12 K. In the case of MnBr 2 :Yb 3 + the estimated t rad = 1.9 ms is about 30 % longer than the experimental lifetime t = 1.4 ms at 12 K. This is attributed to a specifically high concentration of Mn 3 + killer traps in MnBr:Yb 3 + leading to non-radiative losses even at 12 K. Upconversion mechanism in Yb 3 + doped MnCl 2 and MnBr 2 : The extremely weak green luminescence band III shown in Figure 1d is due to cooperative Yb 3 + pair upconversion, which has been reported and studied for a variety of compounds.…”

Inter‐Sublattice Energy Transfer in Rb2MnCI4 Antiferromagnetic Crystals

“…The 337.1 nm N, laser line excites a Mn2+ absorption band. The excitation gives rise to the emission band near 600 nm due to bulk Mn2+ at 15 K [6,7]. As the temperature…”

Luminescence of quasi‐two‐dimensional antiferromagnets (CnH2n+1NH3)2MnCl4 (n = 1, 2, 3)

“…A blue shift is observed below about TN in EAMC as observed in [3] and also in MAMC, but it is clearly not observed in PAMC. Unlike the other quasi-2D antiferromagnets like BaMnF, [4] and Rb,MnCl, [5,6], the emission bands of MAMC, EAMC, and PAMC show a red shift with decreasing temperature. The reason why these crystals show such a different peak shift is not clear at this moment.…”