Charge ordering in Nd2/3Ca1/3MnO3: ESR and magnetometry study

• The electron spin resonance and magnetometry study of Nd2/3Ca1/3MnO3 compound has been done.
• Phase segregated state of the compound below the charge ordering temperature was revealed.
• Charge ordered and charge disordered phases in varying proportions depending on the temperature are coexistent.
• The exchange phase process is the most intense between ~220 K and 180 K.
• At low temperatures the charge ordered to the charge disordered phase ratio is about 4:1.

The evolution of magnetic and electric properties of the narrow-band manganite Nd2/3Ca1/3MnO3 was studied by the electron-spin resonance (ESR), static magnetic field (dc) and resistivity techniques in the temperature range of 100–380 K. It was found that below the charge ordering temperature, TCO≈212 K, the compound is a mixture of the charge ordered and charge disordered phases in varying proportions depending on the temperature. The exchange phase process, when the amount of the charge ordered phase increases under cooling, while the amount of the charge disordered phase decreases is the most intense between ∼220 K and 180 K. At low temperatures, T<160 K, the charge ordered to the charge disordered phase ratio is about 4:1, which is in excellent agreement with previous neutron diffraction data. Both a sharp decrease of the magnetic susceptibility and a huge resistivity increase are evident of the weakening of ferromagnetic correlations and suppression of the double exchange interaction across the charge ordering due to the localization of the charge carriers.