====== Logbooks ====== Download here ({{stm:measurementslog.pdf}}) template for printed logbook. It is very important to keep a rigorous logbook for every measurement ({{stm:measurementslog.pdf}})and for any maintenance action ({{stm:maintenancelog.pdf}}), either on the STM or on the cryostat. A notebook is provided, to make notes. Nevertheless NEVER FORGET to fill in the above provided template AND the below more schematic logbook. Log here the cooldowns: Name_setup/Date-start/He-level start/He-level end/Sample/T-range/Magnetic field range/Date-end/Notes. Under "Notes" report whether He has been refilled during the cooldown. End date is defined when the sample/insert is taken out to air.\\ ^Name STM/setup^ Name ^ Date start (dd/mm/yy)^ He-start (mm) ^ He-end (mm) ^ Sample ^ T-range (K) ^ H-range (T) ^ Date-end (dd/mm/yy)^ Notes ^ |F-STM/green-c.|federica| 10-03-06 | 460 | 200 | HOPG | 300-5 (VTI)|none|15-03-06|He refilled, Z-motor OK.| |F-STM/green-c.|federica| 17-03-06 | 465 | 480 | MoGe(55nm)/Au(2+2nm)|300-4 (VTI)|none |22-03-06 |He-refill, 20-03-06, 0-540mm, 22-03-06, 380-480mm, Z-motor OK first cooldown, 2nd cooldown fails @ 20K.| |F-STM/green-c.|federica| 23-03-06 | 440 | 390 | MoGe(55nm)/Au(2+2nm)|300-4 (VTI)|none |25-03-6 | He-refill, 24-03-06, 0-540mm, Z-motor OK.| |F-STM/green-c.|federica| 25-03-06 | 390 | 540 | LSMO(62nm) on NGO |300-180 (VTI)|none |27-03-06 | He-refill, 27-03-06, 165-540mm, Z-motor stops SUDDENLY at ~180K. NOTE: I set the spring preload higher (Fs,l~45-50gr) before cooling.| |F-STM/green-c.|federica| 27-03-06 | 540 | 400 | LSMO(62nm) on NGO | 290 (VTI)| none | 29-03-06 | Problems: found out that electrical contact sample-to-sample holder was broken. Silver paste cracked off, it explains fully Z-motor "problem" above. | |F-STM/green-c.|federica| 29-03-06 | 395 | 200 | LSMO(62nm) on NGO | 290-4 (VTI)| 0 to +7.88 | 04-04-06 |He-refill:31-03-06, 0-540mm - He-refill:03-04-06, 0-530mm, 03-04-06:magnet quench at 7.88 Tesla. ~20 lts. of Helium are lost. He-refill:03-04-06: 202-410mm. Z-motor OK, at base T and also after quench.| |green-c|federica|05-04-06|--|--|--|--|--|--|Helium refill:0-515mm| |F-STM/green-c.|federica| 05-04-06 | 490 | 270 | LSMO(20nm) on STO | 300-17 (STM)|+0 to +7 | 12-04-06 |He-refill:07-04-06, 0-515mm. He-refill:09-04-06, 0-515mm. He-refill:12-04-06, 20-530mm. Z-motor OK till lowest T| |F-STM/green-c.|federica| 12-04-06 | 200 | 170 | PCMO(80nm) on STO-Nb | 300-50 (STM)| 0 to +7 | 14-04-06 |He-refill:13-04-06, 0-520mm. Z-motor OK.| |F-STM/green-c.|federica| 14-04-06 | 170 | 0 | BSSCO, crystal | 300-50 (STM)| none | 14-04-06 | let cryostat warm up for Easter. Z-motor OK.| |green-c|federica| 15-04-06 |-- |-- |-- |--| -- |-- | start warming up| |green-c|federica| 20-04-06 |-- |-- |-- |--|--|-- | RT (28 Ω) reached, start pumps | |green-c|federica| 24-04-06 |0|540|precooling and cooling|--|--|25-04-6|Problem with λ-plate pumping tube (leak). See blog for explanation. Preoceed with cooling down anyway.| |F-STM/green-c|federica| 26-04-06 |530|410|PCMO(80nm) on STO-Nb|300-50 (STM) |0 to +7.3 | 28-04-06| Z-motor OK. Sample does not show CO-melting. Thinner spot? Magnet OK.| |F-STM/green-c|federica| 28-04-06 |535|400|PCMO(80nm) on STO-Nb|300- 10(STM)|0 to +7.3|17-05-06 |Z-motor always OK. Several He-refills...| |F-STM/green-c|federica/simon|17-05-06|540|several refills |NbSe2 (Leiden Xtal)|300-5 (STM)|none|23-05-06 | Z-motor OK down to base T.| |F-STM/green-c|federica/simon|23-05-06|530|several refills |BSCCO (Ming Li)|300-4 (STM)|none|09-06-06 |Z-motor works OK -sometimes slow- down to 4K on STM for at least 4 different consecutive cooldowns. On 09-06-06 it becomes problematic at low T. Take out sample. Z-motor looks ok, contamination appears to be the problem.| |F-STM/green-c|federica|09-06-06|170|several refills|BSCOO (Ming Li)|300-4 (STM)|none | 15-06-06|2 times at base T and both times Z-motor works. Sample contaminated after 2 cooldowns. Take it out to cleave it. | |F-STM/green-c|federica|15-06-06|540|several refills|BSCCO (Ming Li)|300-4(STM)|none | 20-06-06|Z-motor blocks at 4K due to contamination (while cooling down too fast again T-stm undershooted). At 4K, in liquid, changed the Z-motor driving period from 100μs to 150μs. This change un-blocked the motor, which then worked again and VERY FAST at 4K! Sample looks nevertheless contaminated (wide gaps, no coherence peaks). This and the critical slip-stick of the motor points to contamination problems, maybe now more than normal because of N2 leaking into the He-lines and tank from N2 tank -see issue of λ-plate pumping line being damaged after quench- | |F-STM/green-c.|federica|20-06-06|540|several refills|NbSe2 #8 no I2 (R.H.)|300-4 (STM) |none |27-06-06 |Bias divider by 100. Used metal film resistors. 2 times at base T and both times Z-motor OK. (not even slow). Note: I did not refill LN2 tank this time.| |green-c.|federica|30-06-06|200|n.a.|empty|n.a.|n.a|30-06-06|Found that the bolds of the top flange of the VTI were pretty loose. Due to the fact that the o-ring is made of In, this might cause leaks in the vacuum interspace. This might explain the high boil-off. Pumped for few hrs with rotary and diffusion pump. If there's ice condensed inside the interspace, this won't help much. Only warming up the cryostat will help.| |F-STM/green-c.|federica/simon|30-06-06|490|several refills|LSMO/STO-2.0deg STO. (L309)|300-50|none|17-07-06|Z-motor OK.| |F-STM/green-c.|simon|17-07-06|540|several refills|LCMO/STO-2.0deg STO (L402)|300-100|none|27-07-06|Z-motor OK.| |F-STM/green-c.|simon|17-07-06|540|several refills|LSMO/STO-Nb 5nm (L317)|300-100|none|10-08-06|Z-motor Ok. Sample was taken out once for sample cleaning and tip re-cutting.| |F-STM/green-c.|federica/simon|10-08-06|544|425|LSMO/STO (20nm) (old L307)|300|none|15-08-06|"Streak" problem. Sample looks bad.| |F-STM/green-c.|federica/simon|16-08-06|544|several refills|Old thick flat Au on MoGe (may06)|300|none|21-08-06|Test ("intermezzo")| |F-STM/green-c.|federica/simon|22-08-06|544|several refills|LCMO/STO-Nb 100nm (L407)|300-25|0-7|11-09-06|Z-motor OK. Magnet power supply breaks on friday 25-08-06. The next monday swap broken power supply with older Cryogenic SMS80C from AMC group. After about 1 week imaging becomes more and more difficult (see notes). Contamination? Oxigen depletion of the 1st layers?| |F-STM/green-c.|federica|11-09-06|544|350|Old thick flat Au on MoGe (may06)|300-200|none|12-09-06 |Test ("intermezzo")| |F-STM/green-c.|federica|12-09-06|544|several refills|LCMO/Nb:STO (50nm) L414|300-38|none|18-09-06|a-axis growth clear in topo. On 13-09-06, took out the sample and re-cut the tip. Re-cooled right after. Sample and tip OK, still a-axis growth. Re-cooled to 38K.| |F-STM/green-c.|federica|18-09-06|510|300|Old Au on MoGe (may06)|300-100|none|19-09-06|Z-motor OK. Sample/tip looked contaminated at 100K. | |F-STM/green-c.|federica|19-09-06|544|415|Old Au on MoGe (may06), same as above|300|none|20-09-06|Initially very good conditions. After pulsing the tip, very noisy. See logbook.| |F-STM/green-c.|federica|20-09-06|415|several refills|Old Au on MoGe (may06), same as above|300-35|none|25-09-06 |Z-motor OK. | |F-STM/green-c.|federica/simon|25-09-06|370|several refills |LCMO(50nm)/Nb-STO L414, 3rd piece|300-50|none|28-09-2006|26-09-06, take out again to "restore" the tip. Had to do this several times afterwards. On 28-09-06 "refreshing" the tip does not help anymore. Take out to etch a W tip. Z-motor OK.| |F-STM/green-c.|federica/simon|28-09-06|400|several refills|LCMO(50nm)/Nb-STO L414, 3rd piece|300-44|none|05-10-06|W-tip (etched). Initially topo+STS ok. Z-motor OK.| |F-STM/green-c.|federica|06-10-06|350|several refills|LCMO(50nm)/Nb-STO L414, 4th piece|300|none|06-10-06|PtIr tip, cut| |F-STM/green-c.|federica/simon|09-10-06|544|several refills|LCMO(50nm)/Nb-STO L421|300-50|none |10-06-06 |W-tip (etched). RT noisy topography.| |F-STM/green-c.|federica/simon|19-10-06|500|several refills|LCMO(50nm)/NGO L422|300-149|0 to +7|04-11-06 |Sample straight from sputtering system to STM, only ~3 hrs gap in air, Z-motor OK.| |green-c.|federica|06-11-06|--|--|warm up|--|--| |Cryostat warms up in the w.e. because of a leak in the VTI-He tank separation vacuum space| |green-c|federica|06-11-06|0|470|Pump superinsulaion & interspace|--|--|13-11-06|Diffusion pump: oil had to be changed. Changed (50ml, silicon oil 705) on 10-11-06. Recool on 13-11-06, from RT with Helium directly. Capillaries not flushed - needle valve remained closed and VTI+tank kept on clean He pressure during warm up. 100 lt of helium were used to cool. Needle valve opens, there is flow. Everything OK.| |F-STM/green-c.|federica|13-11-06|470|several refills|LCMO(50nm)/NGO L422|300-200 |none|29-11-06|Z-motor OK. Tip had to be re-cut few times. | |F-STM/green-c.|federica|29-11-06|full|several refills|LCMO(50nm)/NGO L429|300-200|none|23-01-2007|Z-motor OK. Cryostat warmed up during Xmas with sample inside| |F-STM/green-c.|federica|22-01-07|full|several refills|LCMO(50nm)/NGO L429 with Nb-tip (PCAR)|300-30 |none|29-01-07|TEST: Point-Contact Andreev Reflection. Z-motor stops at 30K. When STM out, found Z-motor to be loose (Fs,l=20gr instead of 50gr). This -and some contamination- might explain the problems.|