DOI: 10.48436/tqr2e-4va56
title: Data for the publication "Size Effect on the Thermal Conductivity of a Type-I Clathrate"

description: Context and methodology 



This repository contains the data behind the publication "Size Effect on the Thermal Conductivity of a Type-I Clathrate" (10.3390/cryst13030453).

The dataset was created manually by collecting and ordering the relevant data.

The publication presents and discusses the thermal conductivity of type-I clathrate mesowires with different diameters, measured with a 3-omega technique. The fitting operations and simulations were conducted using data analysis software from OriginLab. 


Description of the data 



Fig5 illustrates the data analysis behind a 3-omega thermal conductivity measurement: Fig5a.dat contains the measured frequency dependence of a 3rd harmonic voltage signal "V_3omega(f)" of a 25um Pt wire, as well as a fit to the data. Fig5b.dat is a representative dataset of a 3-omega measurement done on one 920nm mesowire.  It contains measurements of the 3rd harmonic voltage "V_3omega" as a function of excitation current "I^3" for temperatures ranging from 300K to 80K, in 20K steps and linear fits to the data, demonstrating the "V_3omega" ~ "I^3" dependence. 

Fig6 presents the thermal conductivity and electrical resistivity of the mesowires. The results are the average of measurements of two different mesowires, the dispersion being represented by an error bar: Fig6a.dat contains the lattice contribution to the thermal conductivity "kappa_ph" with an error bar "kappa_ph (Er+-)" and the electronic contribution "kappa_el" with an error bar "kappa_el (Er+-)" as a function of temperature "T" for mesowires of three different diameters 630nm, 920nm, and 1260nm.Fig6b.dat contains the electrical resistivity "rho" with an error bar "rho (Er+-)" as a function of temperature "T" for mesowires of three different diameters 630nm, 920nm, and 1260nm.  

Fig7 compares the accuracy of a modified Callaway model and the original Callaway model in describing our data: Fig7a.dat contains the lattice contribution data "kappa_ph" for the mesowires from Fig6a, as well as a fit to bulk data (obtained from M. S. Ikeda for a different publication and therefore not inlcuded here) using a modified Callaway model. Simulations of the lattice thermal conductivity based on the model with the obtained fitting parameters are included for each mesowire diameter.Fig7b.dat contains "kappa_ph" for the mesowires from Fig6a, as well as a fit to bulk data using the original Callaway and subsequent simulations for the mesowires. 

Fig8 contains "kappa_ph" with an error bar "kappa_ph (Er+-)" as a function of boundary scattering length "lambda", as well as simulations using both the modified and the original Callaway model.

Fig9 contains the calculated figure of merit "ZT" with an error bar "ZT (Er+-)" as a function of temperature "T" for mesowires of three different diameters 630nm, 920nm, and 1260nm.  


Technical details

For each figure there is a corresponding file containing the data shown in the figure. Data files, with the extension .dat, are text files, and named logically after data they contain. 

The dataset does not require any specific software for reading.