Simultaneous magnetic and structural transitions in Nd0.15Ca0.85MnO3 manganite: Magnetization and neutron diffraction studies

• Published in: Solid state communications Vol. 294; pp. 55 - 60
• Main Authors: Dhal, Lakshman, Rayaprol, Sudhindra, Morozkin, A.V., Shukla, N., Geetha Kumary, T., Malik, S.K., Santhosh, P.N., Nirmala, R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2019
• Subjects: Magnetic properties; Magnetocaloric effect; Manganites; Neutron diffraction; Magnetocaloric effect; Neutron diffraction; Manganites; Magnetic properties
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2019.02.006

The manganite Nd0.15Ca0.85MnO3 crystallizes in GdFeO3-type, orthorhombic structure (space group Pnma) at 300 K and orders antiferromagnetically at 112 K (TN). Magnetization-field (M-H) isotherms indicate metamagnetic transition at temperatures below TN. However, metamagnetism does not lead to saturation in magnetization. The magnetization value at 2 K in 140 kOe field is only 0.4 μB/f.u. The isothermal magnetic entropy change (ΔSm) has been calculated using the M-H data and inverse magnetocaloric effect is observed around TN and the maximum value of ΔSm is ∼12.2 J kg−1K−1 at 107.5 K for 140 kOe field change. Powder neutron diffraction study in zero applied field reveals monoclinic distortion of Nd0.15Ca0.85MnO3 crystal lattice and antiferromagnetic ordering of Mn sublattice in ac-plane with wave vector K = [1/2, 0, 1/2] at 125 K. From the neutron data, the Mn magnetic moment value at 3 K is found to be 2.54 μB. Electrical resistivity increases tremendously below TN to an insulating state and shows thermal hysteresis near TN in zero field. Large magnetic fields drive insulator to metal-like transition and negative colossal magnetoresistance of about 70% is realized at 50 K in 70 kOe field and that could be due to the field-induced order. •Simultaneous magnetic and crystal structural transitions are observed in electron doped Nd0.15Ca0.85MnO3.•Inverse magnetocaloric effect occurs in the vicinity of the first order antiferromagnetic transition (TN).•The metamagnetic transition below TN likely drives the colossal magnetoresistance.