Date of Award
1999
Document Type
Thesis
Publication Status
Version of Record
Submission Date
October 2026
Thesis/Dissertation Advisor [Chair]
Neumeier, John
Abstract
Magnetic and electrical properties for La(1-x)Gd(x)0.7Ca(0.3)MnO3 were studied at ambient and high pressure. For x > 0.1 the ferromagnetic saturation moment M is smaller than that expected for complete ferromagnetic alignment of the Mn moments. Gd substitution lowers both the paramagnetic-ferromagnetic transition temperature T(C), the metal-insulator transition temperature T(MI) and dramatically increases the electrical resistivity rho. T(MI) is observed to be significantly lower than T(C) for x > 0.1. The disagreement of T(C) and T(MI) is a result of the A-site ion size difference which causes the coexistence of ferromagnetic La-Ca-Mn-O and antiferromagnetic Gd-Ca-Mn-O phases and leads to the anomalous electrical transport properties. Samples with the largest average A-site ionic radius show the highest T(C) or T(MI) and are least sensitive to pressure.
Extent
71 p.
Recommended Citation
Terashita, Hirotoshi, "Coexistence of ferromagnetic and antiferromagnetic phases in gadolinium-doped lanthanum(0.7) calcium(0.3) manganese oxygen(3)" (1999). Electronic Theses and Dissertations 1990 - 1999. 1415.
https://digitalcommons.fau.edu/etd_general_4/1415
Identifier
FADT15704
Comments
FAU Electronic Theses and Dissertations Collection|Thesis (M.S.)--Florida Atlantic University, 1999.|Charles E. Schmidt College of Science|FAU Electronic Theses and Dissertations Collection