Coexistence of long-ranged charge and orbital order and spin-glass state in single-layered manganites with weak quenched disorder

Abstract

The relationship between orbital and spin degrees of freedom in the single-crystals of the hole-doped Pr${}_{1-x}$Ca${}_{1+x}$MnO${}_4$, 0.3 $\le$ $x$ $\le$ 0.7, has been investigated by means of ac-magnetometry and charge transport. Even though there is no cation ordering on the $A$-site, the quenched disorder is extremely weak in this system due to the very similar ionic size of Pr${}^{3+}$ and Ca${}^{2+}$. A clear asymmetric response of the system to the under- (respective over-) hole doping was observed. The long-ranged charge-orbital order established for half doping ($x$=0.5) subsists in the over-doping case ($x$ $>$ 0.5), albeit rearranged to accommodate the extra holes introduced in the structure. The charge-orbital order is however destabilized by the presence of extra localized electrons (under-doping, $x$ $<$ 0.5), leading to its disappearance below $x$=0.35. We show that in an intermediate under-doped region, with 0.35 $\le$ $x$ $<$ 0.5, the ``orbital-master spin-slave'' relationship commonly observed in half-doped manganites does not take place. The long-ranged charge-orbital order is not accompanied by an antiferromagnetic transition at low temperatures, but by a frustrated short-ranged magnetic state bringing forth a spin-glass phase. We discuss in detail the nature and origin of this spin-glass state, which, as in the half-doped manganites with large quenched disorder, is not related to the macroscopic phase separation observed in crystals with minor defects or impurities.

arXiv commentEPL style; 6 pages, 5 figures

References in corpus (7)

• Colossal magnetoresistance without phase separation: Disorder-induced spin glass state and nanometer scale orbital-charge correlation in half doped manganites
• Theoretical Study of Half-Doped Models for Manganites: Fragility of the CE Phase with Disorder, Two Types of Colossal Magnetoresistances, and Charge-Ordered States for Electron-Doped Materials
• Spin Glasses: A Ghost Story
• Structural and magnetic properties of the single-layer manganese oxide La{1-x}Sr{1+x}MnO4
• Eu${}_{0.5}$Sr${}_{1.5}$MnO${}_4$: a three-dimensional XY spin glass
• Bandwidth-disorder phase diagram of half doped layered manganites
• Variation of charge/orbital ordering in layered manganites Pr1-xCa1+xMnO4 investigated by transmission electron microscopy

Cited by in corpus (5)

• The nanoscale phase separation in hole-doped manganites
• Temperature-dependent and anisotropic optical response of layered Pr${}_{0.5}$Ca${}_{1.5}$MnO${}_4$ probed by spectroscopic ellipsometry
• Combined Effect of Bond- and Potential-Disorder in Half-Doped Manganites
• Structural domain and spin ordering induced glassy magnetic phase in single layered manganite Pr${}_{0.22}$Sr${}_{1.78}$MnO${}_4$
• Correlations and dynamics of spins in an XY-like spin-glass (Ni0.4Mn0.6)TiO3 single crystal system