search.noResults

search.searching

dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
Preparation of Cross Sections of Diffi cult Materials for SEM Imaging


5. Allow the composite to cure, which may take longer than stated on the epoxy label.


6. Remove the fi rm epoxy wafer containing the powder by fl exing the PTFE sheet slightly ( Figure 1F ).


7. Using a stereomicroscope with transmitted light to inspect the sample ( Figure 2A ), choose and mark an area where the powder is concentrated. T e aim is to have many powder grains along the edge that will be polished.


8. With a razor blade, cut the epoxy wafer and overlying Aclar  into an appropriate size and shape for the argon-beam polisher, making the edge to be polished perpendicular to the surface (face of cut surface marked by arrow in Figure 2B ).


9. For thermally sensitive samples, a gold coating can be applied to both sides of the sample using a sputter coater to help dissipate heat. If the gold coating is not too thick, the powder grains will still be visible for easy alignment in the polisher.


10. Place the sample in the polisher so that the Aclar  fi lm is on the side closest to the argon-beam source; polish through the Aclar  fi rst, then the powder-containing epoxy. Align features of interest (that is, the concen- trated powder grains) in the center of the beam.


11. Once the polishing cycle is complete, check the polished edge with the stereomicroscope to assure that the polish has proceeded to the appropriate depth and the desired number of powder grains have been polished. Multiple polishes can be made along the same cut edge.


12. Because the epoxy is nonconductive, additional gold or carbon coating of the polished edge may be needed to control charging during SEM imaging. Procedure for embedding wires . Position the wire in the liquid epoxy and press the Aclar  fi lm down to the surface of the wire ( Figure 3A ); allow the mixture to cure. Cut through the hardened epoxy and the wire with a razor blade, scissors, or wire cutters, depending on the diameter and hardness of the


Figure 4 : Embedded powder of diatomaceous earth. Low (A) and high (B) magnifi cation SEM micrographs of polished cross sections containing many diatoms.


2018 May • www.microscopy-today.com


Figure 5 : Embedded (A) iron-impregnated carbon particles. (B, C) SEM micrographs of polished cross sections.


43


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68