By Topic

Thermal Diffusivity and Related Properties of Colossal Magnetoresistive La _{0.67} Ca _{0.33} MnO _{3} With Various Grain Sizes

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
H. A. Alwi ; Sch. of Appl. Phys., Univ. Kebangsaan Malaysia, Bangi ; R. Abd-Shukor

Using the open-cell photoacoustic technique, we have measured the room-temperature thermal diffusivities of the colossal magnetoresistive material La0.67Ca0.33MnO3, sintered between 1100degC and 1350degC, with average grain sizes 1, 3, 5, and 10 mum. We obtained the thermal diffusivities by analyzing the phase of photoacoustic signals in thermally thick samples using Calderon's method. We found that the insulator-metal transition temperature does not depend on the grain size (TIM ~ 272 K). However, the thermal diffusivity increases with grain size, with values between 0.431 and 0.969 mm2 s-1. Other related electrical and thermal properties, including the electrical conductivity, thermal conductivity, and phonon mean free path, are also dependent on the grain size. The electronic contribution to the thermal conductivity is 2%-3% of the total thermal conductivity for smaller grain sizes (1-5 mum) and increases to about 24% when the grain size is increased to 10 mum.

Published in:

IEEE Transactions on Magnetics  (Volume:45 ,  Issue: 7 )