Fig. 3

Signatures of the manganese charge and orbital order (Mn–COO). a R-T measurements of NCSMO single layers with y = 0.2 and 0.4 in magnetic fields of zero and 9 Tesla (parallel to the layers) which confirm that the effect of the magnetic field is weaker for y = 0.2, meaning that the Mn–COO is stronger in this sample. b Temperature dependent Raman-spectra of the NYN trilayer with y = 0.2 for which vertical offsets are added for clarity. Arrows mark the positions of the “Jahn-Teller-mode” around 480 cm⁻¹ and an additional weaker mode around 230 cm⁻¹ that appears only in the Mn–COO state. c Temperature-dependence of the intensity (upper panel) and the eigenfrequency (lower panel) of the Jahn-Teller-mode obtained by fitting with Gaussian profiles (dotted lines are guides to the eye). d Magnified view of the weak mode at 230 cm⁻¹ showing its absence at 225 K and Gaussian fits at selected temperatures below T_c (Mn–COO). e Temperature dependence of the intensity of the 230 cm⁻¹ mode for the NYN trilayers with y = 0.2 and 0.4. f Evolution of the difference in the c-axis lattice parameters (Δc = c(LSAT)-c(NCSMO)) of the NYN trilayers versus temperature showing a kink at the onset of the Mn–COO around 220 K at y = 0.2 and 200 K at y = 0.4. The error bars in graphs (c), (e), and (f) reflect the accuracy of the fitting procedure