# Thermal diffusivity and related properties of colossal magnetoresistive La0.67Ca0.33MnO3 with various grain sizes

Research output: Contribution to journalArticle

6 Citations (Scopus)

### Abstract

Using the open-cell photoacoustic technique, we have measured the room-temperature thermal diffusivities of the colossal magnetoresistive material La0.67Ca0.33MnO3, sintered between 1100 °C and 1350 °C, with average grain sizes 1, 3, 5, and 10 μm. 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 ($Trm IM} ∼ 272$ K). However, the thermal diffusivity increases with grain size, with values between 0.431 and 0.969 mm2s-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 (15 μm) and increases to about 24% when the grain size is increased to 10 $\mu$ m.

Original language English 5089915 2899-2901 3 IEEE Transactions on Magnetics 45 7 https://doi.org/10.1109/TMAG.2009.2016557 Published - Jul 2009

### Fingerprint

Thermal diffusivity
Thermal conductivity
Photoacoustic effect
Superconducting transition temperature
Electric properties
Thermodynamic properties
Metals
Temperature

### Keywords

• Grain size
• Manganites
• Open-cell photoacoustic
• Thermal diffusivity

### ASJC Scopus subject areas

• Electrical and Electronic Engineering
• Electronic, Optical and Magnetic Materials

### Cite this

In: IEEE Transactions on Magnetics, Vol. 45, No. 7, 5089915, 07.2009, p. 2899-2901.

Research output: Contribution to journalArticle

@article{03fd26d42f514bf0aeb196d1dbcafd49,
title = "Thermal diffusivity and related properties of colossal magnetoresistive La0.67Ca0.33MnO3 with various grain sizes",
abstract = "Using the open-cell photoacoustic technique, we have measured the room-temperature thermal diffusivities of the colossal magnetoresistive material La0.67Ca0.33MnO3, sintered between 1100 °C and 1350 °C, with average grain sizes 1, 3, 5, and 10 μm. 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 ($Trm IM} ∼ 272$ K). However, the thermal diffusivity increases with grain size, with values between 0.431 and 0.969 mm2s-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 (15 μm) and increases to about 24{\%} when the grain size is increased to 10 $\mu$ m.",
keywords = "Grain size, Manganites, Open-cell photoacoustic, Thermal diffusivity",
author = "Alwi, {Hasan Adli} and {Abd. Shukor}, Roslan",
year = "2009",
month = "7",
doi = "10.1109/TMAG.2009.2016557",
language = "English",
volume = "45",
pages = "2899--2901",
journal = "IEEE Transactions on Magnetics",
issn = "0018-9464",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "7",

}

TY - JOUR

T1 - Thermal diffusivity and related properties of colossal magnetoresistive La0.67Ca0.33MnO3 with various grain sizes

AU - Abd. Shukor, Roslan

PY - 2009/7

Y1 - 2009/7

N2 - Using the open-cell photoacoustic technique, we have measured the room-temperature thermal diffusivities of the colossal magnetoresistive material La0.67Ca0.33MnO3, sintered between 1100 °C and 1350 °C, with average grain sizes 1, 3, 5, and 10 μm. 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 ($Trm IM} ∼ 272$ K). However, the thermal diffusivity increases with grain size, with values between 0.431 and 0.969 mm2s-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 (15 μm) and increases to about 24% when the grain size is increased to 10 $\mu$ m.

AB - Using the open-cell photoacoustic technique, we have measured the room-temperature thermal diffusivities of the colossal magnetoresistive material La0.67Ca0.33MnO3, sintered between 1100 °C and 1350 °C, with average grain sizes 1, 3, 5, and 10 μm. 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 ($Trm IM} ∼ 272$ K). However, the thermal diffusivity increases with grain size, with values between 0.431 and 0.969 mm2s-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 (15 μm) and increases to about 24% when the grain size is increased to 10 $\mu$ m.

KW - Grain size

KW - Manganites

KW - Open-cell photoacoustic

KW - Thermal diffusivity

UR - http://www.scopus.com/inward/record.url?scp=67651113617&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67651113617&partnerID=8YFLogxK

U2 - 10.1109/TMAG.2009.2016557

DO - 10.1109/TMAG.2009.2016557

M3 - Article

AN - SCOPUS:67651113617

VL - 45

SP - 2899

EP - 2901

JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

SN - 0018-9464

IS - 7

M1 - 5089915

ER -