Crystal Power CeLL by John Hutchison

[ian middleton]

G'day all,

@Koen:  I tried the ol pull apart D cell trick and found that these days it is rare to find a carbon rod inside. There is a metal spike
coming up from the negative base, a solid thick coating of what looks like manganese dioxide on the inside of the zinc tube and the rest is filled with the alkaline paste which the spike goes into. Messy, very messy 

Today I was playing around with a large pyrites crystal. It's a single unit about 1 cm cube. It has extremely smooth sides with a mirror finish.  I had a couple attempts at plating one of the sides with Gallium but the Ga did not take.
Anyway I found a small bead of Ga and dicided to spot weld it to the pyrites with the 2KV from the bug zapper. That did the trick.

Not expecting to get anything I measured a voltage across the junction. It was a massive 0.3mV  .  Next I looked to see if there was any current with the AVO 8.  1uA.  These values are not going to set the world on fire BUT  the voltage and current have remaind stable all day. I reversed all the meter leads and got -0.3mV and -1uA .

The resistance is 1.6Kohm one way and 210 ohm the other.
I tried to make another one using a clump of small pyrite crystals but got no reading at all, so I may have just got lucky with my first attempt.

I also decided to hook the digital watch up the pyrites cell ( made 2nd March ) and it is running fine on the one cell. This cell is putting out 1.302 volts with the watch as the load. (yeh I know, some load  ).

If I can find a spare oscilloscope I will test to see if the watch places a frequency across the cell, I did notice the cell voltage rise slightly when the watch was attatched.  You never know a small frequency across the cell may make it work better.

Ok I'm off to earn some dosh.
Catch you later dudes  and dudette   


Ian

[Koen1]

@Koen:  I tried the ol pull apart D cell trick and found that these days it is rare to find a carbon rod inside. There is a metal spike
coming up from the negative base, a solid thick coating of what looks like manganese dioxide on the inside of the zinc tube and the rest is filled with the alkaline paste which the spike goes into. Messy, very messy 

Lol yeah, I could have mentioned that part I guess...
It is often a messy business to dismantle batteries, and indeed nowadays many alkaline batteries no longer contain a nice carbon rod.
Many nowadays seem to consist of an isolated metal pin, not uncommonly a cheap nail, stuck in a paste-like material of some kind.
But my main aim was to get the zinc cylinder out, so it doesn't really matter much what kind of electrolyte/conductor mix they have;
I only wanted to try a zinc tube and use a D battery to get one easily.
Nice of you to pick up on it so quickly though.

Today I was playing around with a large pyrites crystal. It's a single unit about 1 cm cube. It has extremely smooth sides with a mirror finish.  I had a couple attempts at plating one of the sides with Gallium but the Ga did not take.
Anyway I found a small bead of Ga and dicided to spot weld it to the pyrites with the 2KV from the bug zapper. That did the trick.

Not expecting to get anything I measured a voltage across the junction. It was a massive 0.3mV  .  Next I looked to see if there was any current with the AVO 8.  1uA.  These values are not going to set the world on fire BUT  the voltage and current have remaind stable all day. I reversed all the meter leads and got -0.3mV and -1uA .

Hey now that ain't bad
and an interesting subtopic you've hit there, too...

Funny, Gallium+Pyrite or more accurately Iron-Gallium-Sulfate, is not really famous for its semiconductive properties as far as I know...
But during a session of infodigging on gallium some time ago I did come across some vaguely related compounds;
To name a few, there is the compound Nickel-Gallium-Sulfide on which a quote from the encyclopedia Brittannica which checks out
referencewise states:

For more than 30 years, scientists had been trying to verify the existence of a ?liquid? magnetic state. In theory, such a state would occur when the magnetic spins of the electrons in a material fluctuated in a disorderly fluidlike arrangement in contrast to the ordered alignment of magnetic spins that produces magnetism. Liquid magnetic states might be related to the way that electrons flow in superconducting materials. Satoru Nakatsuji and co-workers at Kyoto University synthesized a material, nickel gallium sulfide (NiGa2S4), that might demonstrate its existence. The Japanese team and researchers from Johns Hopkins University, Baltimore, Md., and... etc

Then there is an application of Gallium Sulfide as an alternate form of glass with good infrared transparency (from http://www.patentstorm.us/patents/5392376.html):

This invention is directed broadly to transparent glasses exhibiting excellent transmission far into the infrared region of the electromagnetic radiation spectrum, those glasses consisting essentially, expressed in terms of mole percent, of 40-80% Ga2 S3, 0-35% RSx, wherein R is at least one network forming cation selected from the group consisting of aluminum, antimony, arsenic, germanium, and indium, 1-50% Ln2 S3, wherein Ln is at least one cation selected from the group consisting of a rare earth metal cation and yttrium, 1-45% MSx, wherein M is at least one modifying metal cation selected from the group consisting of barium, cadmium, calcium, lead, lithium, mercury, potassium, silver, sodium, strontium, thallium, and tin, and 0-10% total chloride and/or fluoride. Glass compositions consisting essentially, expressed in terms of mole percent, of 5-30% Ga2 S3, 0-10% R2 S3, wherein R is at least one network forming cation selected from the group consisting of aluminum, antimony, arsenic, and indium, 55-94.5% GeS2, 0.5-25% MSx, wherein M is at least one modifying metal cation selected from the group consisting of barium, cadmium, calcium, lead, lithium, potassium, silver, sodium, strontium, tin, yttrium, and a rare earth metal of the lanthanide series, 0-10% total selenide, 0-25% total chloride and/or fluoride, and wherein the sulfur and/or selenium content can vary between 85-125% of the stoichiometric value when doped with Pr demonstrate exceptionally high values of ͌.

Then there is the factoid, supplied mainly from the biochemical field, that Gallium apparently "looks like" Iron to many organisms, which lead to its use
as a bacteriocidal substance to MRSA bacteria according to some cources, and suggests a possible role in the biochemical cycles of certain fungi,
as stated in http://www.webelements.com/nexus/node/1167

"Gallium acts as a Trojan horse to iron-seeking bacteria," said Pradeep Singh (senior author). "Because gallium looks like iron, invading bacteria are tricked, in a way, into taking it up. Unfortunately for the bacteria, gallium can't function like iron once it's inside bacterial cells."

and http://umbbd.msi.umn.edu/periodic/elements/ga.html

Gallium and iron have similar ionic radii, and chelation by iron siderophores has been shown to be a mechanism of gallium uptake in fungi Muller et al, 1985). Gallium accumulation has also been observed in bacteria (Menon et al, 1978), and the toxicity of gallium is likely due to interference with iron-dependent metabolism (Al-Aoukaty, 1992; Olaka et al, 2000). Thiobacillus ferrooxidans can leach gallium from chalcopyrite, and evidence suggests that this organism can directly oxidize gallium sulfide (Torma, 1978).

And of course we know that Gallium-based semiconductive compounds have become very popular in the new colour LEDs, where GaAs and GaN (Gallium Arsenide
and Gallium Nitride) are used. Similar use can be made of Gallium Phosphide (according to http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel3/4100/12123/00557347.pdf?arnumber=557347), and likewise related photoemissive properties of Gallium compounds are and have been studied (as for example http://cat.inist.fr/?aModele=afficheN&cpsidt=15306989 ,"Fabrication and properties of gallium metallic photonic crystals", shows).
In the same category one tends to find the Aluminiu-Gallium compounds, such as Al-Ga-P, aluminium-gallium-phosphide, and similarly of course there are variations
combining known gallium compound semiconductors, so also Al-Ga-In-As, Al-Ga-In-P, Al-Ga-In-S, Al-Ga-Ge-Cu-Fe-As-S, etcetera. Seems if you stay in the right
"zone" you can mix any of these similar group compound semiconductors, resulting in slight variations of similar compounds. Of course we are not really looking
for photoactive materials, but the combining aspect is interesting still. For a nice little list of natural minerals that have a composition in this vacinity I suggest
checking out http://www.galleries.com/minerals/sulfides/class.htm and if you look it up, look at Germanite for a handsome candidate.

In conclusion of this post filled with more or less usefull factoids I would like to quote Wikipedia's "Gallium nitride" page:

Group III nitride semiconductors are recognized as one of the most promising materials for fabricating optical devices in the visible short-wavelength and UV region. Potential markets for high-power/high-frequency devices based on GaN include microwave radio-frequency power amplifiers (such as used in high-speed wireless data transmission) and high-voltage switching devices for power grids. A potential mass-market application for GaN-based RF transistors is as the microwave source for microwave ovens, replacing the magnetrons currently used. The large band gap means that the performance of GaN transistors is maintained up to higher temperatures than silicon transistors.The first Gallium Nitride metal/oxide semiconductor field-effect transistor (GaN MOSFET) was experimentally demonstrated by Weixiao Huang of Rensselaer Polytechnic Institute in early 2008.

So I'm getting the impression we may have a winning ingredient in our Gallium there, Ian!

see you guys later

[Koen1]

Hi all

brief little update:
- "Quirk" still active
- PC running 14+ day datalogging of 4 cells crashed,
now under investigation, fearing the worst
- very experimental plate-based cell versions under
construction, several different mold types, got a few mixes in mind
- came up with possible way to use thermoelectric effect of different
metals to produce a charge on electrodes of a cell (for 'polarisation'
purposes) while inside a 1000 degree C oven/kiln.
(without need for connection to charge source outside it)
- have developed a desire for Galena, for some odd reason
- Rochelle salt based "Hutchison" type cell seems to have gone flat.
  I will have to re-melt the stuff sometime in the near future I guess.
  Will see if I can get a nice high voltage source to charge it this time...
  ... or maybe I should just use my bug zapper, hey Ian?
- am considering to mix up a batch with Gallium, Iron pyrite, Iron oxide,
Silver, perhaps a little Germanium, maybe some Gold. Don't know why the
gold, but since I have a little lying around waiting to be used in a mix I might
as well. Second mix in consideration: the above, plus a little bit of tin, lead
and bismuth. Got that lying around too, and though I'd be surprised if it did
anything with RS, it might with silicate. Both mixes to be tried with silver sand
and R.salt, and with sand/quartz and silicate base mix. Maybe even with sand
and a little bit of waterglass.

All the best
Koen

[ian middleton]

G'day all,

@Koen:  Sorry to hear about your pc, I hope the logger is ok, in this game it is a most valuable piece of test gear.
By shear coincidence I dug out my 2 peltier devices today to see if they would be of any use, it seems Koen you have given
me an idea ( on yer  ).
Nothing wrong with having a desire for galena, I'm quite partial to the stuff myself 

Had a bit of a slack week, basically I've run out of resources. Did however manage to mix up and cook a batch of iron oxide and sulphur in a 1:1 molar ratio. The brittle crystaline mass showed no special electrical properties that I could detect. But may make a good ingredient in a future mix.

The galvanic side of my pyrite cell became painfully obvious when I froze it at -15c for 3 days. The voltage dropped from 1.308V
to 0.898V and the current went awol.

How are you other guys getting on? Got any results we can use 

See you later

Ian

[Koen1]

G'day all,

G'day mate! (crikey?)

@Koen:  Sorry to hear about your pc, I hope the logger is ok, in this game it is a most valuable piece of test gear.

Datalogger seems to be fine, which is good, 'cuz it's worth more to me than the entire old laptop.
Still unclear what caused the crash, am running diagnostic program to figure out where the problem was.
Maybe I should install Ubuntu linux on the old laptop and just run the logger software in Xwin...

By shear coincidence I dug out my 2 peltier devices today to see if they would be of any use, it seems Koen you have given
me an idea ( on yer  ).

Yes yes, you got it. Lol only need to give a hint and you pick it up My idea was actually
simpler, just thinking of attaching a Nickel plate to the one electrode and an Iron plate to the other, possibly using nickel and
iron wire or direct contact... But of course Peltier elements should contain very nice bimetallic junctions than might be even more
usefull. It depends what metals they are and what metal(s) you are using for electrodes. For example, if you're using aluminium
and copper as electrodes you may want to avoid using any of the metals that are positioned in between them in the thermoelectric series,
like titanium, chromium, or tin. But yeah, that's the basic idea. For really high voltages I guess we still need to work something out.

Nothing wrong with having a desire for galena, I'm quite partial to the stuff myself 

Had a bit of a slack week, basically I've run out of resources. Did however manage to mix up and cook a batch of iron oxide and sulphur in a 1:1 molar ratio. The brittle crystaline mass showed no special electrical properties that I could detect. But may make a good ingredient in a future mix.

Hmm interesting, so is the compound now iron sulphate? I just happen to have acquired some cobalt sulphate the other week, it is a nice redish orange crystal grain. Nonconductive, and so far
I have not found a very good use for it, but it is apparently used in glazing as a binder... May be worth mixing with some pyrite and galena...

The galvanic side of my pyrite cell became painfully obvious when I froze it at -15c for 3 days. The voltage dropped from 1.308V
to 0.898V and the current went awol.

Aw.  Well, that's a pity. Then again, a 0.898V static charge is still not bad for a homemade electret,
even if it has zero amps. And although it does indeed suggest galvanic reaction, there is also a chance that there is some pyroelectric effect at play.
Which would obviously also disappear when frozen. But yes, I do get the impression it was galvanic.

And yes, who else is still doing experiments,
and what have you guys managed to come up with?