Study of the physical properties of La2 − xErxTi2O7 (0 ≤ x ≤ 0.075) compounds

• Published in: European physical journal. Applied physics Vol. 59; no. 1
• Main Authors: Amor, N. Ben, Bejar, M., Dhahri, E., Bekri, M., Valente, M.A., Hlil, E.K.
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences 01.07.2012
• ISSN: 1286-0042; 1286-0050
• DOI: 10.1051/epjap/2012120142

New complex magnetic frustrated materials La2 − xErxTi2O7 (0 ≤ x ≤ 0.075) have been synthesized by solid-solid method. The crystallographic and magnetic properties were studied as a function of substitution of the La3+ ion by the Er3+ one. All samples are found to be single phase and crystallize in the monoclinic structure with P21 space group. Magnetic measurements have revealed the presence of dominant antiferromagnetic interactions and the absence of magnetic ordering until a temperature of 2 K. The magnetic study suggests that the Curie-Weiss temperature (θCW) is negative, as expected in the frustrated lanthanide sublattice in the Ln2 – xLn’xM2O7 structure. From the frustration index f = - θCW/TN, we have deduced the presence of a strong frustration phenomenon. The critical properties of the antiferromagnetic behavior, for x = 0.025, 0.05 and 0.075 samples, have been investigated. It was found that the 2D-self-avoiding walk (SAW) model is the best one to describe the critical phenomena.