Electrical properties of fluorine-intercalated layered manganite: La1.4Sr1.6Mn2O7F2

High-Pressure Synthesis, Crystal Structure, and Magnetic Properties of Sr2MnO3F: A New Member of Layered Perovskite Oxyfluorides

“…The low-temperature fluorination used to prepare such systems generally involves a simple F insertion into interstitial sites (such as O vacancy sites), a substitution of F for O, or both . For manganese, fluorination of the oxygen-deficient phases Sr 2 Mn 2 O 5 and Sr 2 MnGaO 5 using XeF 2 as a fluorinating agent results in Sr 2 Mn 2 O 5– x F 1+ x and Sr 2 MnGaO 4.78 F 1.22 containing Mn 3+ /Mn 4+ valence states through the filling of the O vacancy sites with F and the partial substitution of F for O, as shown in Figure a. , Manganese oxides with the Ruddlesden–Popper (RP)-type layered structure having the general formula (AO)­(AMnO 3 ) n , LaSrMnO 4 ( n = 1) and Ln 1.2 Sr 1.8 Mn 2 O 7 ( n = 2), accommodate F in the interstitial sites of the (La/Sr)O rock-salt layers, not in the anion sites of the perovskite block layers, giving LaSrMnO 4 F y ( y = 1, 1.7, 2) and Ln 1.2 Sr 1.8 Mn 2 O 7 F y ( y = 1, 2; Ln = La, Pr, Nd, Sm, Eu, Gd), − as shown in Figure b. Conversely, the oxygen-deficient phase Sr 3 Mn 2 O 6 , which contains pseudosquare and pseudohexagonal tunnels composed of corner-sharing MnO 5 square pyramids, exhibits a stepwise fluorination in which the F atoms occupy first the O vacancies at the equatorial sites of the MnO 5 square pyramid and then the interstitial sites in the rock-salt layers to form Sr 3 Mn 2 O 6 F y ( y = 1, 2, 3) with increasing fluorine content .…”

Structural, electrical and magnetic properties of Nd – A – CoO3 (A = Sr, Ca) Perovskite Powders by Mechanical Alloying

“…The second transition is about the low spin state, intermediate spin state and high spin state that exist in Co ions. However, the low spin state (LS) is t 2g 6 e g 0 with S = 0 for Co +3 ion and t 2g 5 e g 0 with S = 1 for Co +4 ion, the intermediate spin state (IS) is t 2g 5 e g 1 with S = 1 for Co +3 ion and t 2g 4 e g 1 with S = 3/2 for Co +4 ion and the finally, high spin state (HS) is t 2g 4 e g 2 with S = 2 for Co +3 ion and t 2g 3 e g 2 with S = 5/2 for Co +4 ion 20–25 . These are nearly degenerate in energy.…”