Effect of Zn substitution on para- to ferromagnetic transition temperature in La{sub 0.67}Ca{sub 0.33}Mn{sub 1-x}Zn{sub x}O{sub 3} colossal magnetoresistance materials

Journal Article · Mon May 01 04:00:00 EDT 2000 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.373239· OSTI ID:20216219

Awana, V P. S. ^[1]; Schmitt, E ^[1]; Gmelin, E ^[1]; Gupta, Anurag ^[2]; Sedky, A ^[2]; Narlikar, A V ^[2]; Lima, O F. de ^[3]; Cardoso, Claudio A ^[3]; Malik, S K ^[4]; Yelon, W B ^[5]

---

1. Max-Planck-Institut fuer Festkoerperforschung Heisenbergstr-1, D-70569 Stuttgart, (Germany)
2. National Physical Laboratory, K. S. Krishnan Marg, New Delhi 110012, (India)
3. Instituto de Fisica, Gleb Wataghin, UNICAMP 13083-970, Campinas, SP, (Brazil)
4. Tata Institute of Fundamental Research, Homi Bhabha Road, Bombay 400005, (India)
5. Research Reactor Facility, University of Missouri, Columbia, Missouri 65211 (United States)

Structural, magnetic, and thermal measurements are carried out on the La{sub 0.67}Ca{sub 0.33}Mn{sub 1-x}Zn{sub x}O{sub 3} system with x=0.0-0.50. The structural characterization of the samples is done by Rietveld analysis of their neutron diffraction patterns. Zn substitutes at Mn site isostructurally until x=0.30. Oxygen content remains nearly invariant with x. Magnetic and thermal measurements as well as the electrical resistance show a para- to-ferromagnetic transition at T{sub p}, which decreases with an increase of x. For low Zn concentration (until x=0.075) the decrease dT{sub p}/dx is smaller than for the larger concentrations of Zn. Relative decrease dT{sub p}/dx at higher concentrations (x>0.10) is similar to that observed earlier for the La{sub 0.67}Ca{sub 0.33}Mn{sub 1-x}Fe{sub x}O{sub 3} system. For the transition at T{sub p}, the related change of magnetic entropy ({delta}S{sub trs}) are calculated from the heat capacity data and indicate that for x=0 the expected value {delta}S{sub trs}=12.8 J/mol K is recovered. (c) 2000 American Institute of Physics.

• OSTI ID: 20216219
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 87; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM OXIDES
EXPERIMENTAL DATA
LANTHANUM OXIDES
MAGNETIC PROPERTIES
MAGNETORESISTANCE
MANGANESE OXIDES
NEUTRON DIFFRACTION
PHASE TRANSFORMATIONS
SPECIFIC HEAT
STRUCTURAL CHEMICAL ANALYSIS
ZINC OXIDES