Study of canonical spin glass behavior in Co doped LaMnO3

Farooq H Bhat,Deshdeep Sahdev,Ravi Kumar,Manzoor A Malik,Gitansh Kataria,Ghazala A Khan

doi:10.1063/9.0000142

Abstract

Temperature-dependent magnetic and a.c. susceptibility measurements were done on single phase polycrystalline LaMn1-yCoyO3 (y = 0.1, 0.4) samples. The field cooled and zero field cooled magnetic measurements performed indicate the presence of spin glass state which is established using a.c. susceptibility measurements. The a.c. susceptibility data analyzed using Arrhenius and Vogel–Fulcher (VF) law reveal the presence of canonical spin glass.

Highlights

INTRODUCTIONJoy and co-workers found that LaMn0.5Co0.5O3 exists in two FM phases, representing various spin and valence and spin states of Mn and Co. The lower TC (150 K) phase contains Co2+ and Mn4+, while a higher TC (225 K) phase has high spin (HS) Mn3+ and low spin (LS) Co3+ ions
The perovskite manganites RMnO3 (R = La, Nd, etc.) have been the subject of exhaustive research because of competing interactions among magnetic, electronic, and structural phases
The x-ray diffraction (XRD) pattern displays a peak shift towards higher 2θ values as y increases indicating the lattice contraction due to Co substitution at the Mn site resulting in the decrease of overall unit cell volume

Summary

INTRODUCTION

Joy and co-workers found that LaMn0.5Co0.5O3 exists in two FM phases, representing various spin and valence and spin states of Mn and Co. The lower TC (150 K) phase contains Co2+ and Mn4+, while a higher TC (225 K) phase has high spin (HS) Mn3+ and low spin (LS) Co3+ ions. Scitation.org/journal/adv done in ZFC and FC mode at 0.01T applied field, exhibit the occurrence of a SG state in the samples LaMn1-yCoyO3 with Co concentration y = 0.1 and y = 0.4. To authenticate these findings frequency-dependent a.c. susceptibility measurements were made at different frequencies of 21 Hz, 1101 Hz and1701 Hz in the presence of the applied field of 0.0004 T and analyzed using Arrhenius and Vogel–Fulcher (VF) law

EXPERIMENT

X-ray diffraction

Magnetization and ac susceptibility

CONCLUSIONS