Figure 1

The magnetic and structural phase transitions of ${\mathrm{La}}_{1-x}{\mathrm{Sr}}_x{\mathrm{MnO}}_3$ in the $T-x$ region of interest. (a) SQUID magnetization measurements at 5 G (blue curve), and ac-susceptibility measurements (black curve), performed on a high quality $x=0.125$ single crystal. (b) The $T-x$ phase diagram, in the doping range $0\le x\le 0.2$, as reconstructed from Refs. 7, 8, by including magnetization and NMR data from the present work. The yellow-white hatched low temperature region around $x=0.125$ is characterized by nucleation of FM O-type nanodomains into the ${\mathrm{O}}^{\prime \prime }$ matrix. ($\mathrm{FMI}=\mathrm{FM}$ insulating, $\mathrm{FMM}=\mathrm{FM}$ metallic). The inset in panel (a) shows the temperature variation of the magnetic moment near the JT structural transition.Reuse & Permissions

Figure 2

(a) Zero field ${}^{139}\mathrm{La}$ NMR spectra of LSMO for $x=0.075$, 0.125, and 0.20, at 5 K. (b) The ${}^{139}\mathrm{La}$ NMR rf-enhancement experiments for $x=0.075$, 0.125, and 0.20 at 5 K. The signal intensity $I$ is recorded as a function of the applied rf field $B_1$. The obtained $I$ vs $B_1$ curves follow an asymmetric bell-shaped law with maximum at $n\gamma B_1\tau =2\pi /3$, where $\tau$ is the rf pulse duration, $\gamma$ the nuclear gyromagnetic ratio, and $n$ the rf-enhancement factor [23].Reuse & Permissions

Figure 3

${}^{139}\mathrm{La}$ NMR rf-enhancement measurements for ${\mathrm{La}}_{1-x}{\mathrm{Sr}}_x{\mathrm{MnO}}_3$ with (a) $x=0.075$, (b) $x=0.125$, and (c) $x=0.20$. The contour plots show the NMR signal intensity $I$ as a function of $B_1$ and temperature. The plot in the middle shows clearly that the ground state of the LSMO $x=0.125$ compound consists of two subsystems differing in their magnetocrystalline anisotropy.Reuse & Permissions

Figure 4

${}^{55}\mathrm{Mn}$ NMR spectra of LSMO, $x=0.125$ (○), at 5 K and 25 K. The black solid lines in the upper panel are the Mn spectra at 5 K for the canted FM insulator $x=0.075$ (double-peak signal), and the FM metal $x=0.20$ (central single-peak signal). The insets in blue color [analogous to Fig. 2b] show the variation of the signal intensity $I$ vs the rf field $B_1$ (scaled in Gauss) at the frequency positions of the start of the $B_1$ scales.Reuse & Permissions

Figure 5

${}^{139}\mathrm{La}$ (circles) and ${}^{55}\mathrm{Mn}$ (stars) spin-spin relaxation time $T_2$ measurements of ${\mathrm{La}}_{0.875}{\mathrm{Sr}}_{0.125}{\mathrm{MnO}}_3$ as a function of temperature, at two different rf fields (${}^{139}\mathrm{La}$), and two different frequencies (${}^{55}\mathrm{Mn}$), which correspond to the O and ${\mathrm{O}}^{\prime \prime }$ phase components.Reuse & Permissions