Lab Book- Synthesis of YBCO

This is the abridged version of what I have done so far. The other posts have my thoughts, and musings on this project. This post will be more succinct and a quick reporting of procedures.

6/19
Obtained the following masses of reactants:
0.8483 g Y2O3
2.9622 g BaCO3
1.7900 g CuO

Combined the reagents and ground into homogeneous powder with mortar and pestle.

Transferred powder to jar mill, added zirconia beads and ethanol (solvent)

Set apparatus to mill overnight

6/20
-Removed slurry and balls from jar mill, placed in large glass petri dish
-Rinsed milling bottle with ethanol to remove slurry stuck to walls
-Placed petri dish in 120 degree oven to evaporate solvent.
-Removed dry petri dish

-Using forceps, remove jar mill balls and rinsed with acetone to recover mixture stuck to the balls. (mostly ineffective)
-Placed petri dish in oven to evaporate acetone.
- When dry, set to cool, scraped powder from petri dish onto weighing paper

-Made 4 pellets (approximately 1-1.5 g each)

-Crucible and pellets set to react in furnace (48 hours at 930 degrees C, ramp 5 degrees/minute)

6/23:
- Removed pellets from furnace (color change from gray to black)
- Ground with mortar and pestle
- Verified phase with x-ray diffraction

- Made 3% by mass solution of poly-vinyl alcohol in DI water
- Added 5-6 drops of solution (PVA did not dissolve completely, used magnetic spin and extracted solution using pipet)
- Homogenize YBCO and PVA into slurry (added some DI water)
- Placed in 60 degrees C oven to dry overnight

6/24:
- Re-ground with mortar and pestle
- Pressed into 1.0 g pellets

6/27: (lapse in days due to lack of oxygen available)
- Post-anneal in tube furnace (oxygen flow)
Vessel: alumina boat
48 hours at 940 degrees C
Gas flow: 1.0 mL per minute

6/30:
- X-Ray diffraction of sample

7/1:
- When testing Meissner Effect, levitation of pellets was weak.
- Re-annealed in oxygen
40 hours @ 940 degrees C
Gas Flow: 1.5 mL per minute

7/7:
They work!!!

- Started Batch #2 (similar preparation with only a few slight differences)

Changes:
- Perform PVA treatment after first annealing
- Use alumina crucible rather than boat (prevent pellets from sitting against alumina during heating- remove chance of some interaction between alumina and pellets)

Reference used for this synthesis:
She, J.L. & Liu, R.S. J. Chem. Educ. 2008, 85,825-826.