Hi,can you edit the value and enter manually inputs? Then you can get data from ref papers or technical datasheets.
If you can look into the Material Data for Simulation: https://www.ansys.com/en-gb/products/materials/materials-data-for-simulation
Or if you have access to Ansys Granta Products (EduPack for teaching or MI / Selector for research/industry). Here a screenshot from Selector.