arXiv subjects

A. A. Mukhin

Publications and source records attributed to A. A. Mukhin.

40 records · Page 3Linked to original sources

arXiv2000

High-field AFMR in single-crystalline La_{0.95}Sr_{0.05}MnO_3: Experimental evidence for the existence of a canted magnetic structure

High-field antiferromagnetic-resonance (AFMR) spectra were obtained in the frequency range 60 GHz < ν< 700 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.

cond-mat↗

arXiv1999

ESR study in lightly doped La_(1-x)Sr_(x)MnO_(3)

This is the first systematic ESR investigation of La_(1-x)Sr_(x)MnO_(3) single crystals for Sr concentrations x < 0.2. The rich phase diagram of this compound, which is dominated by the Jahn-Teller effect of Mn^(3+), is a matter of actual interest in connection with giant magnetoresistance phenomena. The ESR signal, which is due to both Mn^(3+) and Mn^(4+), directely probes the suppression of the Jahn-Teller distortion with increasing Sr concentration and reveals all characteristic structural and magnetic phase transitions.

cond-mat.str-el↗

arXiv1998

Positive magnetoresistance and orbital ordering in La(1-x)Sr(x)MnO(3)

We report on detailed transprort measurements of single crystalline La(1-x)Sr(x)MnO(3) (x<=0.2). We have found a giantpositive magnetoresistance in the compositions range between 0.1<=x<=0.125 and give an explaination in terms of orbital ordering due to the interplay between superexchange interactions and Jahn-Teller distortions.

cond-mat.str-el↗

arXiv1998

The phase diagramm of La{1-x}Sr{x}MnO3 revisited

We report on detailed sucseptibility and magnetization studies in La{1-x}Sr{x}MnO3 for x<=0.2. We arrive at a phase diagram which shows a ferromagnetic ground state for 0.1<=x<=0.15 followed by a canted antiferromagnetic phase at higher temperatures, not in agreement with present canonical conjectures. The phase diagram indicates the importance of structural aspects and superexchange interactions for the magnetic phases at low Sr concentrations.

cond-mat.str-el↗