Freshly Ground Grains

Bulk Exposed by Grinding Grains using Mortar & Pestle

• To expose the bulk of grains or large crystallites, we grind the sample in a mortar.
• If possible, we try to make a fine powder.
• It is best to flow Argon over the mortar while grining to minimize oxidation of freshly exposed bulk.  To minimize the heat effect of grinding, we grind fast at first and then slow down again with Argon flowing over the mortar.
• Before using the mortar and pestle clean them with water and acetone, and then a bit of light sanding with fine sandpaper, and then a final spray with acetone. Then the mortar is reasonable clean.
• If we see any powder remnants then we clean the mortar with either dilute HCl acid or Oxalic acid followed by rinsing with distilled water.
• Some grains of very tough materials (nitrides, carbides) are difficult to grind as received.  We take some of these grains and smash them with a hammer and then grind.