Dielectric signature of charge order in lanthanum nickelates

Abstract

Three charge-ordering lanthanum nickelates La2-xAxNiO4, substituted with specific amounts of A = Sr, Ca, and Ba to achieve commensurate charge order, are investigated using broadband dielectric spectroscopy up to GHz frequencies. The transition temperatures of the samples are characterized by additional specific heat and magnetic susceptibility measurements. We find colossal magnitudes of the dielectric constant for all three compounds and strong relaxation features, which partly are of Maxwell-Wagner type arising from electrode polarization. Quite unexpectedly, the temperature-dependent colossal dielectric constants of these materials exhibit distinct anomalies at the charge-order transitions.

arXiv comment7 pages, 6 figures

References in corpus (17)

• Complexity in Strongly Correlated Electronic Systems
• Materials with Colossal Dielectric Constant: Do They Exist?
• Non-intrinsic origin of the Colossal Dielectric Constants in CaCu3Ti4O12
• Colossal dielectric constants in transition-metal oxides
• Multiferroicity due to charge ordering
• Electronic correlations in the iron pnictides
• Colossal dielectric constants in single-crystalline and ceramic CaCu3Ti4O12 investigated by broadband dielectric spectroscopy
• Colossal dielectric constant up to GHz at room temperature
• Stripe order at low temperatures in La{2-x}Sr{x}NiO4 for 1/3 < x < 1/2
• A Novel Dielectric Anomaly in Cuprates and Nickelates: Signature of an Electronic Glassy State
• New phase transition in $P{r}_{1-x}C{a}_{x}Mn{O}_3$ system: evidence for electrical polarization in charge ordered manganites
• Dielectric response of the charge-ordered two-dimensional nickelate La1.5Sr0.5NiO4
• Anomaly in the dielectric response at the charge orbital ordering transition of crystalline Pr0.67Ca0.33MnO3
• Oxygen and Strontium Codoping of La2NiO4: Room Temperature Phase Diagrams
• Weak ferromagnetic spin and charge stripe order in La[sub 5/3]Sr[sub 1/3]NiO[sub 4]
• Transmission-electron-microscopy study of charge-stripe order in La(1.725)Sr(0.275)NiO(4)
• Charge order, dielectric response and local structure of La5/3Sr1/3NiO4 system