Lyndon Edward Smith

13 Questions 3 Answers 0 Followers

Questions related from Lyndon Edward Smith

Using Jonscher's power law, how do I fit this?

This is from dielectric spectroscopy data for a metal-oxide ceramic that has two major phases and a small amount of a third phase present. It's a plot of AC conductivity vs angular frequency for...

29 July 2024 1,602 4 View

Can I use an image of the same sample in two different publications?

I'm trying to submit a paper, but two different manuscripts are being prepared. One is by me and one is by a collaborator who is using my samples. I know it's unethical to reuse the same data in...

26 June 2024 6,249 2 View

When performing Le Bail refinement in GSAS-II, should you refine sample displacement at all?

Sample displacement in microns is found under the "Sample Parameters" item in the menu tree. Should this be refined at all during Le Bail refinement?

03 June 2024 718 0 View

What kind of instrumentation is needed for temperature-controlled impedance spectroscopy?

I'm trying to find modern instrumentation for doing impedance spectroscopy on ceramic pellets (diameter = ~12.5 mm, thickness = ~1 mm) across different temperatures - up to several hundred degrees...

12 April 2024 6,027 0 View

How do I get a good dispersion of BiFeO3 in thermoplastic polyurethane (TPU)?

I'm trying to get a good dispersion BiFeO3 in TPU using probe ultrasonication. I then take the mixture and try to get a good film using a doctor blade method. So far, I can't seem to get as good a...

06 February 2024 7,573 0 View

Should you refine the atomic positions of dopants in Rietveld refinement? How should dopants be handled in general?

Let's say you're refining a structure like BiFeO3 that has a dopant like La in the A-site and/or Ti in the B-site. You add them to the list of atoms manually (I'm using GSAS-II). Should you refine...

08 November 2023 7,808 0 View

How to measure bond angles in Vesta with a doped CIF?

I did refinement in GSAS-II of BiFeO3 doped with Dy in the Bi site and Zn/Ti in the Fe site. The Zn and Ti were added in GSAS to a CIF that was preprogrammed with Dy already. When I open the...

27 October 2023 6,437 2 View

Is there free software for Windows machines that can do electron density maps?

There's G-Fourier for Linux and MacOS. I can't make it work for Windows however. Is there some Fourier analysis software that would allow me to make 2D and 3D electron density maps on a Windows...

19 October 2023 8,503 4 View

In an X-ray diffractometer, to what does "goniometer radius" refer?

Does it refer to the distance from the incident slit box to the sample or the distance from the sample to the detector? This is a general question, but the diffractometer in question is a Rigaku...

16 June 2023 8,267 0 View

When running a refinement in GSAS, should you refine atomic positions if you add a dopant?

Let's say I have an XRD pattern for BiFeO3 doped with 5 at-% Ti occupying the B-site (nominally BiFe0.95Ti0.05O3). I start with a BiFeO3 CIF file and add the Ti on the Fe site (same position with...

31 March 2023 4,043 2 View

How do I know which atoms go in which Wyckoff positions?

I'm currently in the process of trying to make CIF file because none is available on COD. I have the space group, and I can check the Wyckoff positions for that space group online. What I can't...

02 January 2023 1,958 0 View

What is the best way to prepare thin film polymer samples for tensile testing according to ASTM standard D882?

I am trying to prepare a large number (24 in total) of thermoplastic polyurethane samples for tensile testing. I have 8 different samples and want to make 3 of each. Some of the samples will...

09 December 2022 1,433 0 View

What set of experiments needs to be performed to demonstrate that a material is ferroelectric?

I am also trying to prove that a powder I have is showing ferroelectric properties, but I was under the impression that demonstrating hysteresis in the polarization curve is enough. Apparently, I...

21 November 2021 3,322 5 View