Dysprosium (new) - Periodic Table of Videos

0:00 It's right there.

0:06 Disprosium.

0:06 16 years ago, we made our first video about dprosium.

0:11 You can see we've got a very thin foil sample of of dprosium.

0:15 It was rather a boring element then and it's really gone up in the popularity

0:21 scale and is now become really quite

0:24 important technologically and also in fundamental science.

0:31 In the original video, Pete found a small sample of disprosium

0:36 sheet in a drawer in our store downstairs.

0:42 this wonderful sample of dprosium.

0:46 So Neil and I went down to look for the sample that Pete had got.

0:57 It was gone.

0:59 Someone must have taken it for their experiment

1:03 without admitting it because it's quite expensive metal.

1:07 Fortunately, our friend Anthony Litman and his collaborators in the company G.

1:14 Chapman have provided us with two really nice samples.

1:20 In fact, three two pieces of metal and also

1:25 a lump of so-called dendritic gprosium metal where it has crystallized

1:32 in a sort of fibrous form which looks really good

1:36 and it was too nice to try and destroy chemically.

1:40 So, I'm going to keep it to display.

1:46 We're going to show you some really quite nice reactions of the metal.

1:51 But before that, we're going to talk about its magnetic properties.

1:58 Disprosium is one of the so-called rare earth

2:01 elements and it's in the periodic table above californium,

2:07 the very radioactive element.

2:10 But surprisingly, it's attracted to magnets really quite strongly.

2:16 Neil has a very powerful small magnet.

2:20 And with this magnet,

2:21 he managed to lift up the larger lamp of dysprosium right off the table.

2:34 He also took some filings of dprosium metal.

2:40 You know, we tend to use a file to form finely divided metal.

2:45 And he could move the filings round

2:48 on the sheet of paper with his magnet underneath.

2:51 I quite like that.

2:53 But the exciting chemistry and magnetism we'll get to in a minute.

3:01 This broium metal dissolves quite easily in hydrochloric acid

3:11 and Neil and Brady had quite a lot of fun.

3:16 Bubbles away release of hydrogen and the disposium chloride

3:22 that's formed is completely soluble in water or weak acid.

3:26 Fortunately, we didn't have to use that solution

3:30 for our reactions because my colleague Peter

3:34 Harvey lent us a whole bottle of disposium

3:38 chloride which he was using for magnetic experiments.

3:44 And so we had a nice solution of disposium chloride and we

3:48 filled a whole series of test tubes to try different reactions.

3:57 The first reaction was with carbonate solution

4:06 and you get a nice precipitate of dprosium carbonate.

4:10 It's white.

4:12 Most of the salts of the rare earth's elements are colorless.

4:18 We then tried the hydroxide.

4:26 And we got another precipitate that was white, but it looked slightly different.

4:32 It's what chemists call slightly gelatinous, more like a jelly.

4:41 Sulfide.

4:39 Then we tried the sulfide that also produced a precipitate.

4:53 And this really quite exciting because normally when we try these tests,

4:58 there's one test after another when nothing exciting happens.

5:03 And Brady says the professor doesn't know what he's doing.

5:07 In all these tests, we put the dprosium salt into a test

5:12 tube containing whatever the reagent was hydroxide carbonate and so on.

5:20 We also did it with sodium chromate which is quite

5:26 strongly yellow the solution and when you add the dprosium chloride

5:31 you get a precipitate of the dprosium chromate but because

5:36 the solution is so colored anyway you don't see it very well.

5:43 So we reversed it, filled a test tube with dprosium chloride

5:49 and dropped in some chromate and then you saw a beautiful yellow precipitate.

6:04 Finally, not to disappoint Brady, we decided to do panganate,

6:11 which as you know is a very dark purple color this in solution.

6:17 And we dropped some panganate

6:19 into the disposium chloride solution and nothing happened.

6:26 So Brady was pleased.

6:28 Professor wrong again.

6:35 What do you think happened?

6:37 You made us do that.

6:40 Yeah.

6:41 We then thought we would add acid to all of these test tubes.

6:47 The dprosium carbonate bubbled releasing CO2 and dissolved.

6:54 We added hydrochloric acid.

6:56 So we were regenerating the disprosium chloride.

7:01 Similarly, the disposroium hydroxide dissolved up and the sulfide,

7:11 though there was also a bit of a smell of rotten eggs,

7:15 hydrogen sulfide, which is quite nostalgic to me.

7:19 I used to use hydrogen sulfide at school.

7:22 with the chromate.

7:24 It was interesting because the solution changed color almost

7:29 instantaneously because chromate can in acid solution can form dromate.

7:37 There's an equilibrium between dromate and chromate

7:41 one is orange and the other is yellow.

7:52 But then just to snub Brady when we put

7:56 the hydrochloric acid and the permanganate it went colorless.

8:04 Oh there you go.

8:06 Not because of the disprosium

8:08 but because hydrochloric acid reacts with panganate

8:12 to produce chlorine but still it was a nice color change.

8:17 So we had a series of reactions which really look nice

8:21 and demonstrate that despium has really

8:24 quite similar chemistry to the other rare

8:28 earths and this is part of the problem that the chemists

8:33 in the 19th century had when they were trying to isolate this element.

8:38 In fact, the name dprosium comes from the Greek

8:42 word I think it's despositos which means difficult to separate.

8:50 Dprosium was discovered by the French chemist

8:53 Paul Lok who also discovered gallium and samarium.

8:59 He was really quite an interesting character.

9:02 He wasn't a professional chemist.

9:05 He didn't work at the university.

9:07 He worked in the second bedroom of his two-bedroom apartment.

9:13 Don't try separating elements in your bedrooms.

9:16 The way he identified these elements was largely by looking

9:21 at the spectra of the elements when they were heated in a flame.

9:28 And he noticed some extra lines which he assigned to disprosium.

9:33 But then trying to actually isolate the disposium was really very hard.

9:39 I suppose in those days there was

9:42 a huge driving force to discover another element.

9:46 So people kept on doing it until they found an element.

9:51 Let's now look at the more modern chemistry

9:55 and the real interest in disprosium apart from using it

10:01 in alloys to make better magnets for things like wind

10:05 turbines has been in what is called single molecule magnets.

10:13 You probably know that the information on many

10:17 computers on hard disks are stored magnetically.

10:21 And over the years, the amount of space each bit that is stored requires has got

10:30 smaller and smaller and it still requires quite

10:35 a large collection of atoms to store one bit.

10:40 However, there are a number of new

10:43 compounds which are so-called single molecule magnets where

10:49 just one magnetic atom in the middle

10:52 of the molecule is enough to store this information.

10:56 So you can align the magnetic moment of that atom and it

11:01 will stay there and won't flip

11:03 back because otherwise you'd lose the information.

11:07 So one direction represents a one and one direction represents zero.

11:10 Zero, right?

11:11 Okay.

11:12 Well, people have not got as far as actually representing things,

11:16 but they've got as far as making materials where

11:21 the magnetic information will be preserved for a relatively long time.

11:27 The first molecule that was made was by a chemist

11:30 called Layfield at University of Sussex in the south of England.

11:35 The dprosium atom was sandwiched between two C5 rings and it had

11:42 some extra groups here as well so that each atom was nicely isolated.

11:48 This molecule would retain its magnetism up to about the temperature

11:54 of liquid nitrogen which is 77 Kelvin the boiling point of liquid nitrogen.

12:01 More recently, a group in Manchester working with a group in Australia

12:08 have made a new compound which has a distrosium atom sandwiched between

12:17 two nitrogen atoms and there's almost a straight line between the two

12:23 nitrogens and the disprosium and this keeps

12:27 the dprosium atom very well isolated.

12:31 ated.

12:31 So once its magnetic moment is aligned, it doesn't lose it at all easily.

12:38 This compound operates at a higher temperature.

12:42 It still needs a low temperature, but I believe it's above 100° Kelvin.

12:49 The rare earths are not terribly rare,

12:53 but at the moment much of the supply of dprosium comes from China.

12:59 Some of it comes from Myanmar

13:01 and deposits have now been discovered in Australia.

13:07 There are quite a few minerals that contain despium, but it's not pure.

13:13 It's just one of several components and not

13:16 the biggest metallic component of a particular ore.

13:22 So what is really the key to making Dprosium is

13:28 to separate it from a rather impure at a reasonable

13:35 economic cost and over the last 20 years or so

13:40 the price of disposium has rocketed up and down.

13:46 I have no idea how much the sample that we were generously given is worth,

13:51 but it is still quite a rare element to have in the lab.

14:02 One of the things that our gallant technician Neil really loves

14:07 is sprinkling fine powder of the elements into a Bunson burner.

14:24 Certainly, Drosium did not disappoint.

14:28 We weren't sure what to expect, but it produced very bright sparks.

14:43 One experiment completely bleached out the video

14:48 camera picture because the light was so bright.

15:01 I thought it looked really beautiful.

15:03 I think together with some of the other rare elements fireworks,

15:08 I'd really like to have a Dsprosium firework as well.

15:28 As you know, we like to observe what happens in our experiments.

15:33 And at the end, just before Neil was clearing up his fume cupboard,

15:39 he noticed that some of the tiny particles

15:43 of dprosium salt on the floor of the fume cupboard,

15:47 probably the oxide from when he burnt the metal fragments

15:53 or possibly the chloride had absorbed water from the atmosphere.

15:58 These are so-called hyroscopic compounds.

16:03 They absorb water from the atmosphere and in principle not with despium

16:10 but with other salts you can actually

16:14 get water from the atmosphere and there are groups in California who are trying

16:21 to make emergency water supplies for travelers

16:27 for soldiers in the field using compounds that will attract water from the air.

16:35 They've even got water from the air in Death Valley.

16:39 Thanks for showing your support by watching this video.

16:42 If you'd like to support us further

16:43 and appear here on our periodic table of patrons,

16:47 why not check out the links below?

16:49 You can see we haven't actually got a Dsprosium supporter at the moment,

16:53 but you can choose any element.

16:54 Here are some of the people on there at the moment.

16:58 And supporting us on Patreon means you'll also get access to extra goodies,

17:01 extended footage, behind the scenes stuff.

17:04 Check it out.

17:05 And as I said, there are links down below.

17:08 Also easy to obtain.

17:10 It's a major component of air.

17:12 It's quite cheap to make.

17:14 Also, it has a convenient temperature of 77° Kelvin -96° centigrade.