High-field antiferromagnetic resonance in single-crystallineLa0.95Sr0.05MnO

Abstract

High-field antiferromagnetic-resonance ͑AFMR͒ spectra were obtained in the frequency range 40 GHz ϽϽ700 GHz and for magnetic fields up to 8 T in twin-free single crystals of La 0.95 Sr 0.05 MnO 3 . At low temperatures two antiferromagnetic modes were detected, which reveal different excitation conditions and magnetic field dependencies. No splitting of these modes was observed for any orientation of the static magnetic field excluding the phase-separation scenario for this composition. Instead, the full data set including the anisotropic magnetization can be well described using a two-sublattice model of a canted antiferromagnetic structure.

Magnetic ground state of low-doped manganites probed by spin dynamics under magnetic field

“…On the other hand, in case (ii), the superposition of two spin excitation spectra is expected, a doubly degenerate AF branch for the AF matrix, superposed on a F branch for F domains, giving rise to three branches under applied field. RPE experiments [4,5], which probe the q ¼ 0 modes under applied field, determine two spin wave excitations with F and AF character, in agreement with the case (i). Neutron scattering [6,7] which measures the full q-dependence, reveals additional features, distinct from mean field calculation, leading to a third picture of a modulated canted AF ground state.…”

“…Neutron scattering experiments have been carried out on triple axis spectrometers at LLB (4F) and at ILL (IN14, H ¼ 0 T. We notice that the low-energy branch shows an anisotropic dispersion unlike the observations at lower doping[5]. Under magnetic field H//b, the evolution of Bragg peaks intensities versus H reveals that the F-component of the spins rotates from c-…”

Structural first-order transformation in La2/3Ba1/3MnO3: ESR study

“…The electron-spin resonance acts as a useful tool for studying phase diagrams of complex magnetic materials both in the paramagnetic regime (normal ESR) [27][28][29] and in the mode of magnetic ordering (ferromagnetic resonance, FMR) [30,31]. A significant advantage of the ESR technique is a good sensitivity to magnetic and structural inhomogeneities [32,33].…”

Magnetic transitions and electrical transport in Bi-doped lanthanum strontium manganites

“…In addition, some weak impurity peaks from SrMnO, BiSrMnO, and Bi 2 O 3 phases were found [14]. The crystal structure for the compositions La 0.7-x Bi x Sr 0.3 MnO y was found to be rhombohedral structure [18][19][20]. Lattice parameters and cell volume were calculated and tabulated in Table 1.…”