Questions and Answers

0 Like 0 Dislike

Shahid Arshad

Dielectric for materials

Dear,

I would like to know the source of dielectric functions for gold, silver and titanium dioxide in this simulation tool. thanks

reagrds

Shahid 

Report abuse

2 Responses

  1. 0 Dislike

    AbderRahman N Sobh

    Hi Shahid,

    Silver Phys. Rev. B 6, 4370–4379 (1972) Johnson and Christy

    Gold, evaporated (Johnson & Christy 1972, PRB 6, 4370)

     

    The function we use for TiO2 is little bit old and we just a constant 2.61E-8:

    Ligand Dielectric

    1 2 3 0 0

    wave n k

    .3      2.61 1e-8

    .4              2.61 1e-8

    .5              2.61    1e-8

    .6              2.61 1e-8

    .7              2.61 1e-8

    .8              2.61    1e-8

     

    I believe we made this based off the average refractive index value given by Devore, 1951 (http://refractiveindex.info/?shelf=main&book=TiO2&page=Devore-o).

    Reply Report abuse

    Please login to answer the question.

  2. 0 Dislike

    AbderRahman N Sobh

    Hi Shahid, I just wanted to add more thing in case you have another dielectric formula/file which you prefer:

    Typically, we have used the site (http://refractiveindex.info/) to look up the table of values. In the graph of the refractive index at the bottom there are some checkboxes, be sure to select "n" and "k". Then, underneath the bottom-right portion of the plot there is a 3-line-button-icon which contains some data saving options. You can either save a csv and edit that, or perhaps easier is to choose the "View data table option" and just copy and paste that into a file (since there are no commas in this view).

     

    In order to use these values in the nanoDDSCAT tool you can do either of two things:

     

    1) Inside the nanoDDSCAT tool choose a single constant value, this gives you a menu inside the tool that you can just place the value in which gets applied to all wavelengths.

     

    2) Upload a .txt file with your dielectric values formatted like so:

    Material -- Author information/source

    1 2 3 0 0 = columns for wave, Re(n), Im(n), eps1, eps2

    wave n k 

    1937.25 1.09 13.43

    1610.18 0.76 11.12

    1393.08 0.6 9.439

    1215.53 0.48 8.245

    1087.58 0.36 7.217

    .

    .

    .

     

     

    For example:

    Copper -- Johnson and Cristy PRB 1972 6 4370

    1 2 3 0 0 

    wave n k 

    1937.25 1.09 13.43

    1610.18 0.76 11.12

    1393.08 0.6 9.439

    1215.53 0.48 8.245

    1087.58 0.36 7.217

     

    Best,

    AbderRahman (Abby) Sobh

    Reply Report abuse

    Please login to answer the question.